Jeep p0420 code

Jeep Grand Cherokee P0420: Catalyst System Efficiency → Below Threshold → Bank 1 | Drivetrain Resource (700r4transmissionhq.com) ... fault codes P0420 and P0430; catalyst efficiency below thresholds, bank 1 and 2. I was in disbelief of a (or 2) catalyst failures on a vehicle with low miles. I have the “right diagnostic equipment” that ...

Matt Konkle. August 27, 2015. Tweet. Torque Staff Report. This method is used to retrieve OBD I and OBD II diagnostic trouble codes from your YJ, TJ, XJ, ZJ, and early WJ Jeep models. Insert the key into the ignition. Turn the ignition On-Off-On-Off-On within 5 seconds. Record the 2-digit DTC as displayed by the flashing MIL.The P0420 is a diagnostic trouble code mainly for Catalytic System Efficiency Below Threshold (Bank1). This code is stored in memory when the ECM would have detected a low efficiency in the catalytic system. The ECM determines the cat con's working efficiency with two sensors. As such, the Catalytic System Efficiency (CSE) metric regulates ...August 27, 2015. Tweet. Torque Staff Report. This method is used to retrieve OBD I and OBD II diagnostic trouble codes from your YJ, TJ, XJ, ZJ, and early WJ Jeep models. Insert the key into the ignition. Turn the ignition On-Off-On-Off-On within 5 seconds. Record the 2-digit DTC as displayed by the flashing MIL.Reattached and air blows from all vents. The Jeep sat for a week. I took it out for a quick trip to pick him up at school and used the air conditioning. Before the end of the 5 mile round trip, the check engine light lit up. Would a P0420 code be thrown due to a vacuum leak and possibly the PO disconnected the line to keep the code from coming up?Trouble code p0420. Jump to Latest Follow. 6K views 8 replies 3 participants last post by TJerry Dec 9, 2014. gel04tj Discussion starter. 30 posts · Joined 2013. #1 · Dec 8, 2014. Check engine light on with this code, replaced both o2 sensors on manifold (code said bank 1) & I used oem mopar sensors. Had code erased & drove it, check engine ...That P0420 codes is one of the most unambiguous of all the diagnostic trouble codes. That code is thrown when the upstream and downstream O2 sensors both have the same "switching frequency." That means that the cat is doing very little to change the exhaust gas composition. In other words, the cat needs to be replaced.

PLEASE HELP! Codes P0420 and P0420. Hi all! I am new to the forum. I have a 2011 GC Limited, V6, 3.7L, 160K Miles. A few months ago, the check engine light came on with the codes P0420 and P0430. Since then, I have replaced all 4 O2 sensors and the gas cap (I heard that may be an issue too).These codes illustrate two different sides of the engine. Engines with an inline configuration can contain just one bank. The P0430 code basically means the same thing as P0420 on the other bank, and therefore you can check out my guide about the P0420 code, which is much more detailed. RELATED: Bank 1 vs Bank 2 - Sensor 1 & 2Aug 20, 2020 · As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Dreaded P0420 Code -- after resolving misfire. Friends, I'm getting the P0420 code, Catalyst System Efficiency Below Threshold (Bank 1). Long story short, I drove several hundred miles with a misfire caused by a gunky fuel injector in cylinder 1 (codes: P0301, P0201). Hated to keep driving on it, but I was far from home when the misfire …Sorry guys I made a mistake withe the type of vehicle.No More p0420 Code in 2007 Jeep Compass Catalytic converter code keep popping up fix.Code P0420 stands ...In this video I replace the rear O2 sensor (bank 1) on a 2008 Jeep Grand Cherokee 3.7 V6. This vehicle has a trouble code P0420 stating the catalyst system e...

common-sense-answer January 12, 2016, 9:50pm 15. P0420 Code. Last Time I Checked, That Particular DTC (Diagnostic Trouble Code) Was The Most Commonly Occurring Code Found On Vehicles With Illuminating CELs (Check Engine Light). As others have pointed out, that code doesn't necessarily mean the cat is failing, replace it.Vídeo explicativo sobre el CÓDIGO DE FALLA P0420. Descubre qué significa, por qué ocurre y cómo solucionarlo correctamente.LEER SOLUCIÓN DEL CÓDIGO OBD2 EN...The P0456 is a generic code stating that the Engine Control Module (ECM) detected a small leak from the evaporative system. This leak was detected during a self-test. For the code to come on, the test must fail two times in a row before the Check Engine Light comes on.2005 Jeep Liberty P0420 Code Hey guys i have a 2005 jeep liberty i was getting a P0420 code O2 sensor problem. I thought i would have to change the sensor, but a while back i had a ford ranger with the same problem I looked at the sensor and the wires and saw the the wire from the sensor was resting against the catalytic and the wires had ...P0463. Fuel Level Sensor A Circuit. High. The OBDII reader says "$10 Generic" at the top of the screen. Don't know what that means. It's now doing it around 3/4 tank of fuel, but today when I went to read the code, the gauge didn't register at all, so I think my sending unit is now completely bad.

Mytime fairview.

Engine codes P0627 & P0420. 3365 Views 3 Replies 4 Participants Last post by dei38bud, ... A forum community dedicated to all jeep owners and enthusiasts. Come join the discussion about performance, engine swaps, modifications, classifieds, troubleshooting, maintenance, and more!P0340 definition: Camshaft Position Sensor Circuit Malfunction. Issue Severity: SEVERE - Stop driving immediately. Repair Urgency: Fix this code immediately (same-day if possible) to avoid internal engine damage. Diagnosis: The vehicle may be difficult to start and the driver may also experience a lack of power when driving.MeanGreenZJ. 1708 posts · Joined 2011. #9 · Feb 2, 2012. My guess is that the P0430 code is triggered by the P2098 code. Which points to a failed 02 sensor or circuit, exhaust leak or mechanical issues. Or as said above a flash update issue.Find a complete list of Jeep Wrangler check engine light codes in this CJ's article. The store will not work correctly in the case when cookies are disabled. Grab Up to 24% Off Sitewide: Here's to 40 Years! ... P0420: Catalyst Efficiency (Bank 1) P0430: Catalyst Efficiency (Bank 2) P0440: General EVAP System Failure: P0441: EVAP Purge System ...More Problems / code p0420. So to bring everyone up to speed in the last 2200 miles my motor was replaced, twice. Read about it here. Then after about another 1100 miles the water pump failed. On Oct 1st the check engine light came on. That was for the catalyst system, code p0420. Read about that here. I hoped that the O2 sensor just had a quirk.Kiwi Jeeper Discussion starter · Nov 30, 2008. I have had my cat converter and front O2 sensors replaced last year (about 12 months ago). Since then I have driven about 12k kms. This weekend I got the check engine light and the code that has come up is P0420 (M) - catalyst converter efficiency below threshold.

Catalytic converter replacement. How to replace a catalytic converter DIY with Scotty Kilmer. Catalytic converter replacement in your car (Code P0420). Tips ...If the voltage of the downstream oxygen sensor decreases, and begins to fluctuate like the upstream oxygen sensor, it means that the oxygen levels are too high and the Power Control Module will then store the P0420 trouble code and can be the source of the hard to start issue you’re experiencing.This video will show you how to fix a seemingly fine catalytic converters (FOR OFF-ROAD ENVIRONMENTS ONLY) so that your check engine light turns off. The ben...P0420 Catalyst Efficiency (bank 1) Code. 2007 JKU with 70K miles threw the P0420 engine code this morning on the way to work. Thought it might be related to the recent TSB I had completed for the gas fill-up overflow issue but alas it's not. Doing some research and I found some posts that stated the federal emissions warranty should cover any ...2004 jeep wrangler unlimited p0420 code.Sensor subaru bank p0420 impreza 2006 code engine located tribeca where check side 2010 capitalistic reads threshold below front efficiency Misfire jeep fix. The check engine code P0420 reads capitalistic system efficiency belowNOTE: Take note that while the cods listed below are not strictly related to P0420 – “ Catalyst System Efficiency Below Threshold (Bank 1)”, these codes often appear with P0420. P0421 – “Warm Up Catalyst Efficiency Below Threshold (Bank 1)”. P0422 – “Main Catalyst Efficiency Below Threshold (Bank 1)”. P0423 – “Heated ...trouble codes P0420 & P0432. I have an 04 wrangler with 4.0 (6 cyl) I took it to my mechanic and had them check it out. They told me that the computer gave trouble codes P0420 and P0432- insufficient flow through catalyst. They said that the O2 sensors seemed to be switching correctly and that they didn't seem to be mirroring each other.258 posts · Joined 2016. #3 · Apr 1, 2018. The p0302, specially if it has happened more than once and regularly is typically a sign that it has the infamous head issue. Mine happened at 37k miles, took it in. Dealership kept it for a day and said that it did have the head issue and replaced the head.Does Cataclean really fix a P0420 / P0430 error code and catalytic converter. Cataclean Link: https://amzn.to/33t8RVQ Second channel for easy to follow Home ...We may earn a commission for products purchased through links on this pageJeep Liberty - KJ (02 to 07) ... You can't get P0420/P0430 codes without properly functioning O2 sensors. Nov 21, 2017 #11 A. adamkrz Full Access Member. Joined

So I bought a used Jeep Patriot from a dealership in 2015 and it had about 80,000km on it already. I have since put another 80,000km on it. So I am about 160,000km. ... a P0420 code by itself is usually the cat. If you had a P0420 and another code like an O2 sensor performance code it may be the sensor, but in this case, I think you're looking ...

throwing the PO420 code but I have a question. I'll try to keep this short since I have a tendency to be wordy. 96 ZJ, 4.0L, all stock except for the audio system, 181K miles. A couple months ago I took the Jeep in to resolve some recall items. One of them was the PCM reprogram and catalytic converter inspection.Catalytic converter cleaner. How to clean catalytic converter DIY with Scotty Kilmer. Catalytic converter clogged and problem code P0420. How to fix and repa... The P0420 code signals a low catalyst system efficiency. This code suggests that the oxygen levels are below the desired threshold (Bank 1), which most often results from problems with your car ... Catalytic converter cleaner. How to clean catalytic converter DIY with Scotty Kilmer. Catalytic converter clogged and problem code P0420. How to fix and repa...So I then Called Magnaflow to get me some replacement cats. I ordered Magnaflow 99204HM which are the standard Universal cats for the 3.7L Had them welded on by shop. I reset the Code at the shop and the next day going to work I get Code p0420, Which is Low Bank 1..... Kind of odd that it jumped from Bank 2 to Bank 1 like that.This page is meant to help you troubleshoot the Jeep Wrangler P0420 trouble code. It covers the P0420 code’s meaning, symptoms, causes, and possible solutions. P0420 is the most common OBDII code and is virtually never a breakdown risk.Definition: Catalyst Efficiency (Bank 1) Description: General Operation: The State of Change (SOC) catalyst monitor uses the signals from both the Upstream and Downstream …Cherokee grand 9-24-13 2008 jeep grand cherokee 3.7 code p0325 part 2 2004 jeep grand cherokee p0420 and p0325: stft b1 -10.9% ltft b1 7... Cherokee grand crd gear selector remove fix replace Jeep wj grand cherokee 02s oxygen sensor guideJeep grand cherokee 05-10-fault codes p0315 & p0335 fixed!-crankshaft Jeep cherokee grand b196 c2112000 jeep ...Code P0420 Dodge Description. The Engine Control Module monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2.When the P0420 code appears, the catalyst system efficiency is below the threshold for a particular engine bank, often referred to as Bank 1. This code is related to the vehicle's catalytic converter and oxygen sensors. The primary purpose of a catalytic converter is to reduce harmful emissions from the engine by converting toxic gasses, …

Knock sensor 2014 chevy cruze.

Friendly center cinema.

Jeep Grand Cherokee & Commander Forums. ZJ Grand Cherokee Forum. P0420 code advice. Jump to Latest Follow 572 views 1 ...Sep 30, 2018 · Jeep Compass P0420 Code Symptoms. The P0420 code in a Jeep Compass will often be thrown if one of your vehicle’s oxygen sensors is not functioning correctly. There are rarely drivability issues associated with P0420. For most people, the first sign that anything is wrong is the service engine soon light coming on. P0420 Code. Jump to Latest Follow ... A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the discussion about reviews, performance, trail riding, gear, suspension, tires, classifieds, troubleshooting, maintenance, for all JL, JT, JK, TJ, YJ, and CJ models! ...So a week ago it pops the P0420 code (Catalytic Converter Efficiency below threshold, Bank 1). I cleared it thinking it was a fluke but then got it again about 50mi later. ... '09 Jeep GC SRT8 Red Rock,6k hid fogs and high beams with 6 high mod,6k LED Interior,Billet Flat Black Shorty Antenna, Black Rims, Drilled/Slotted R1's w/ StopTechs, Red ...The P0420 code on a Chevy indicates the catalytic converter is not operating at maximum efficiency. A faulty oxygen sensor, a damaged catalytic converter, or an engine misfire can cause this. Getting the catalytic converter replaced by a mechanic is the common fix. Why Does My Jeep Wrangler Have a P0420 Code?CODE P0420 DODGE DART, CHRYSLER 200, JEEP CHEROKEE COMPASS RENEGADE, RAM PROMASTER CITY, FIAT 500X, FIAT TOROIf you have engine light on and code P0420 and y...258 posts · Joined 2016. #3 · Apr 1, 2018. The p0302, specially if it has happened more than once and regularly is typically a sign that it has the infamous head issue. Mine happened at 37k miles, took it in. Dealership kept it for a day and said that it did have the head issue and replaced the head.55 posts · Joined 2015. #7 · Mar 17, 2015. P0394-CAMSHAFT POSITION SENSOR INTERMITTENT - BANK 2 SENSOR 2. I believe this is the left bank intake camshaft position sensor. Sensor is on top of the valve cover towards rear.Code Number Code Description Related Codes P0456 Evaporative Emission Control (EVAP) System Leak Detected (Very Small Leak) P0442 - EVAP Leak Detected (Small Leak)A suspect is wrong sensors. 3) check fuse #16 in PDC and relay oxygen downstream in PDC. a wag - INCORRECT O2 SENSORS, let us know. P0138-1/2 O2 SENSOR SHORTED TO VOLTAGE. P0420-1/1 CATALYTIC CONVERTER EFFICIENCY. P0141-1/2 O2 SENSOR HEATER FAILURE. P0161-2/2 O2 SENSOR HEATER FAILURE. ….

Check Engine Light and P0420 and P0430 Codes. So, your Check Engine light is on, and you've got either a P0420 or P0430 code, on your OBD-II scanner. This "Catalyst system efficiency below threshold" code is triggered when your car's computer (the powertrain or engine control module (PCM or ECM)) detects a catalytic converter issue. 1A ...Been getting the p0420 code and if deleted it comes back in about 2 weeks so ---- I stop and get a gallon of laquer thinner and put it in the tank--- ... I talked to the Jeep mechanic changing the engine in my Jeep about the cats. The cats were giving off a fine residue which, due to the close proximity of the cats to the exhuast valves, the ...02 WJ with P0420 code. So I've been doing some work to my WJ. I've got it down from 4 CEL codes to 1, the dreaded P0420. I went ahead and changed my catalytic converter with a brand new one but still have the code. I head that it could possible be related to the O2 sensors. I took some graphs of the voltages with the Torque Pro app.Code P0430 means that the downstream oxygen sensor from the catalytic converter on bank 2 detects the cat isn’t operating to efficiency standards, based on factory specifications. The P0430 trouble code is considered generic, meaning it occurs on vehicles of any type and model. The P0430 shows a problem with the emissions system.2813 posts · Joined 2010. #5 · Dec 6, 2010. P0155 is an O2 sensor heater fault code... but its a 2/1 code (bank 2 upstream) so more than likely not related to your current P0420 code. 4.7's regularly break exhaust studs (the back 2) and you would know by a ticking noise while the vehicle is running.What Causes the Catalytic Converter to Fail. How To Diagnose Trouble Code P0420: Catalyst Efficiency Below Threshold (Bank 1). TEST 1: Checking For a Broken Catalytic Converter. TEST 2: Checking The Output Of The Rear Oxygen Sensor. TEST 3: Manually Inducing A Lean Condition.October 03, 2023 -. P0420 stands for a code that signals the "Catalyst System Low Efficiency" issue and is a relatively common occurrence, especially with cars that are only driven over short distances. As the catalytic converter plays a vital role in reducing emissions and maintaining the overall performance of your vehicle, it is important to ...6.Get a Replacement O2 Sensor That Fits Your Car. The P0157 code refers to a potential problem with the #2 sensor on Bank 2 or its circuit. This code applies to the downstream oxygen sensor located right behind the catalytic converter. If your OBD-II scanner registers this code, you can either let your mechanic handle it or address the issue ...Our RX330 had a CEL come on at 252,000 miles with code P0420. Shop recommended catalytic converter replacement for around $1500, but for $25, I decided to try Cataclean. I ran two bottles back to back along with Shell premium, cleared the code and the vehicle just surpassed 264,000 miles. The CEL has been off ever since.We may earn a commission for products purchased through links on this page Jeep p0420 code, P0420 Code. How to fix it. Don't spent tons of $$$. ~This also true for the po430 Code!Check out My Amazon Auto Accessories Store! Lets make that Weekend job..., The standard 3.0L Hurricane I6 Twin Turbo engine with Stop/Start delivers more horsepower, torque,and efficiency than the 6.4L V8 engine. In addition, its available 4,468- KG maximum towing capacity1 means you won't compromise anything when it comes to strength. HORSEPOWER. 493., on my 2004 Jeep wrangler I am getting trouble code P0420. I looked up the code and it tells me my catalyst system has low efficiency. Does this mean I need to change my catalytic converter? Experience: 25 years of experience, Certified Subaru Technician and Nissan factory trained., 2813 posts · Joined 2010. #5 · Dec 6, 2010. P0155 is an O2 sensor heater fault code... but its a 2/1 code (bank 2 upstream) so more than likely not related to your current P0420 code. 4.7's regularly break exhaust studs (the back 2) and you would know by a ticking noise while the vehicle is running., What It Is: The P0456 code in your Jeep Wrangler, identified using an OBDII scanner, indicates a small leak in the evaporative emission control system.It is often associated with codes like P0420, P0441, and P0440. Impact: P0456 typically doesn't pose an immediate threat to your Wrangler's driveability, but addressing any service engine soon light promptly is always wise., Tech Notes. The P0440 code means that the control module has detected a leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the most common cause that triggers the P0440 code. ⚠ Check if your Jeep have Safety Recalls., If you’re an avid DIYer and a car enthusiast, you may have come across the dreaded “Code P0420” at some point. This diagnostic trouble code is related to your vehicle’s catalytic c..., Dreaded P0420 Code -- after resolving misfire. Friends, I'm getting the P0420 code, Catalyst System Efficiency Below Threshold (Bank 1). Long story short, I drove several hundred miles with a misfire caused by a gunky fuel injector in cylinder 1 (codes: P0301, P0201). Hated to keep driving on it, but I was far from home when the misfire …, P0420 Code. Hi, new to the forum and new Jeep owner. I've got a 2007 Grand Cherokee Limited with the 5.7. I had it checked out before I bought it and it showed a fault with a downstream O2 sensor which I replaced, the CEL was cleared, and I drove it 50 miles on the highway. Light stayed off for about a day., The downstream sensor might switch real slow or slightly compared to the upstream but when its starts switching at around the same rate and voltage as the upstream sensor then the PCM throws the P0420, knowing that if the catalyst was working then the dowstream sensor would not be switching like the upstream is., The P0420 code signals a low catalyst system efficiency. This code suggests that the oxygen levels are below the desired threshold (Bank 1), which most often results from problems with your car ..., P0420 Code. My wife's 2015 2.4 4x4 threw a P0420 code which seems to indicate either a bad cat or bad o2 sensor. I was going to throw some sensors at it ($16 on RockAuto) but then I realized the federal emissions warranty on the cat is 80k 8 years and we bought it May 2015 and have 74k on it. So we are right on the tail end of the warranty ..., Even slight variations in the air/fuel mixture will cause the converter temperature to rise significantly. The "Catalytic Converter Efficiency" Diagnostic Trouble Codes (DTCs) P0420 and P0430, are among the top 10 DTCs technicians face. And while the description might imply a failed converter, odds are the ultimate fault lies somewhere else., Ok, so about 3-5 months ago when I first got the Jeep, she had a emissions code problem, no biggy, went through a little bit of a fight to get the right NTK sensors (I installed Bosch ones first) and all was good, the code was gone. Then I had a battle with the TPS sensor. Got that sorted out and now I. Can't get the P0420 (bank 1cat below ..., El código OBD2 P0420 es uno de los problemas más comunes en los vehículos. Este código indica una disminución en la eficiencia del sistema de catalizador del vehículo y puede tener varias causas, como problemas con el sensor de oxígeno, el convertidor catalítico y el sistema de escape.. Los síntomas más comunes incluyen problemas en la aceleración y aumento del consumo de combustible., Jeep Liberty P0420 Code Symptoms. The P0420 code in a Jeep Liberty will often be thrown if one of your vehicle’s oxygen sensors is not functioning correctly. There are rarely drivability issues associated with P0420. For most people, the first sign that anything is wrong is the service engine soon light coming on., How to diagnose code P0420 on a Jeep. Typically, you'll find out about P0420 because your malfunction indicator lamp or "check engine light" turned on & you or a mechanic diagnosed the problem with an OBD II code scanner like this one from Bluedriver. You may experience a very slight reduction in engine power from reduced exhaust flow, as well., Jeep 4.0L inline six-cylinder engines tend to be configured this way. While the OBD-II scanner can distinguish between a P0420 code and a P0430, it never hurts to double-check for issues that may cause a problem with the catalytic converter. There can be different causes for vehicles like a BMW with code P0420 and P0430., =====Claim your FREE engine code eraser 👉 https://free.nonda.co 👈=====Engine Code JEEP P0038 Saving Repair ..., P0420 is a diagnostic trouble code that relates to the catalytic converter on bank 1 in Dodge vehicles. When this code appears, it suggests that there is a malfunction with the catalytic converter, specifically on bank 1. The catalytic converter is responsible for reducing harmful emissions from the vehicle's exhaust system., The P0420 code indicates that the ECM has detected underperformance of the catalytic converter's efficiency on Bank 1. Either it is a faulty catalytic converter, or it could be an electronic oxygen sensor. The ECM uses two O2 sensors to detect whether the catalytic converter is functioning properly, whether there is a problem with the fuel ..., Has your check engine light recently turned on? Are you seeing the dreaded error code P0420 on your vehicle’s diagnostic scanner? Don’t panic just yet. Code P0420 is a common issue..., SAVE MONEY and buy Motor Oils and Car Parts online - FREE SHIPPING!!! RECOMMENDED BY THE PEOPLES GARAGEhttp://amzn.to/1ck3B2wHow to Fix a P0420 or P0430 Code..., A week ago I got a P0420 code, which is a catalyst efficiency below threshold. Can anyone help me pinpoint the issue? If it's just the O2 sensor I would be delighted, but I'm not so sure. ... A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the discussion about reviews, performance, trail riding, gear, suspension ..., Thanks for checking out my channel. Please like Share and subscribe thank youAlso Check me out and follow me on Check out some Merchandise atTeespring ..., If code P0420 shows up on an OBD code reader, it means the engine's harmful gasses production has increased. That means the operational efficiency of the catalytic converter is below its threshold. The two oxygen sensors have measured its efficiency and deemed that it is low. That is why you see the P0420 code., P0133 Jeep Code - O2 Sensor Circuit Slow Response Bank 1 Sensor 1 - Code Popularity: 37,482 Views - Repair Importance Level: 2/3 - Repair Difficulty Level: 2/3. Table of contents. Created and updated by William Orellana on Jun 14, 2020. Possible Causes; Tech Notes; Description; How to Fix;, The standard 3.0L Hurricane I6 Twin Turbo engine with Stop/Start delivers more horsepower, torque,and efficiency than the 6.4L V8 engine. In addition, its available 4,468- KG maximum towing capacity1 means you won't compromise anything when it comes to strength. HORSEPOWER. 493., Vídeo explicativo sobre el CÓDIGO DE FALLA P0420. Descubre qué significa, por qué ocurre y cómo solucionarlo correctamente.LEER SOLUCIÓN DEL CÓDIGO OBD2 EN..., Code Number Code Description Related Codes; P0420: Catalyst System Efficiency Below Threshold (Bank 1) P0430 - Catalyst System Efficiency Below Threshold (Bank 2), P0420 Code Jeep Grand Cherokee. P0456 code jeep liberty 2004 jeep grand cherokee p0420 and p0325: stft b1 -10.9% ltft b1 7... 26 Feb 2024. Cherokee o2 2004 wj wrangler p0051 02s jeepspecs fixya v8 sentra nissan patriot liter cargurus Cherokee grand Jeep ba16. 2000 Jeep Grand Cherokee 4.7. Codes. P1596, p0204, p0207., Many factors can cause the car computer to register DTC P0420 on Toyota or any car model. This makes it challenging to diagnose and fix the problem. Engine running rich or lean. Malfunctioning upstream or downstream oxygen sensor. Leaking fuel injectors. Lousy catalytic converter. Lousy engine coolant temp sensor., 2009 3.7 V6 WK 133,000 miles. Unlikely that cleaning throttle body killed the Cat. Manually moving the throttle should produce no issues. Have someone put a scanner or oscilloscope on the front and rear O2 sensors to confirm the P0420. That person will look at the wave forms of each O2 sensor.