My check engine light has been coming on and off and it seems to show P0420 for catalytic converter. The light stays off for about a week and it'll come on for a day or two and off again.
Wouldn't a failed converter stay failed? Can P0420 be triggered by loose/bad gas caps?
I checked out a 2006 Prius yesterday a guy is selling. It had the CEL on (not sure why somebody would try and sell a car with that, but anyway). He said that it's because they get gas at a station that consistently doesn't tighten the gas cap enough but by the time the tank is down to 1-2 bars the light always goes away. Although I don't doubt his story, I absolutely doubted the cause. So I took it to get the code pulled and it was P0420, which is catalytic converter threshold below efficiency.
View 15 RepliesMy wife's car is a 2002 Prius, 149 k miles. Lately the check engine light has been coming on. I took it to the dealership, and their assessment is that the catalytic converter needs to be replaced. They are recommending about $2,000 + of repairs. While I am contemplating the practicality of investing that much in keeping this car going I'm wondering if it harmful or dangerous to continue operating this vehicle.
View 12 RepliesI just moved to Colorado with my 2009 Prius and on the fifth day here the check engine light went on and the dealership said my catalytic converter failed. Luckily I was still under warranty. Is this related to the altitude or just a coincidence?
View 3 Replies2004 Chrysler Sebring Sedan, 4 cylinder dual-overhead cam. My check engine light came on this morning and the code came out as the catalytic converter. The car seems to be running fine, at least no recent changes. I'm debating replacing this vehicle soon, and I'm wondering if it's worth working on the catalytic converter. I recently replaced the cam shaft position sensor as well.
View 5 RepliesDoes this mean the DPF is shot? I believe its integral with the cat. whats worth checking first?
View 2 RepliesTitle says it. Cat is done. Threw code p0420 and am experiencing hesitation at WOT. Already replaced my front o2 (cbfa) and now I'm debating whether or not to get a new downpipe. I daily the car and am wondering if keeping the car as is for a while will damage anything. Cts turbo has a sale for a catless downpipe.
View 5 RepliesSo today my CEL came on. I immediately looked at my mileage and I was EXACTLY at 500m past my oil change the other day. I checked the dip stick and lo and behold, it was about 3/4" past the full marker. I took it back to the oil change place and had them drain it down to a good level.
I had driven from NH to NY this week. I filled up my gas tank on my way home from NY. Gas cap was on nice and tight for sure.
The code is still on (not sure how many miles or drive cycles is required) for something to clear. I figured it was perhaps due to too much oil added. I decided a few hours later to take it to AutoZone and grab the diagnostic code. It's a P0420 code (Cat System efficiency below threshold: Air leak in exhaust before rear HO2S, AF Sensor Error, Fuel System Fault, Faulty Catalytic Converter).
My cat converter is rattling on driver's side and check engine light is on. Rattle is the inside of the converter, not the heat shield. How much $ and what kind of converter replacement is recommended?
View 10 RepliesI have a 2003 Toyota Corolla, mileage app. 106,000. Check engine light first came on when driving to destination 40+ miles away (most of my driving is shorter, around-town trips). My mechanic said code is P0420 and so they reset it and said if it comes on again that I need a new cat converter. It did not come on until about 6 weeks later when I was on a longer trip again (had driven about 40-50 miles). Can you tell me if the P0420 code absolutely means that a new cat. conv. is needed or if it could possibly be a sensor or something else hopefully less costly than a new cc?
View 3 RepliesI have a 2001 Honda Odyssey with 90000 miles. Lat last year around Oct/Nov time frame, check engine light came on. I took my vehicle to a local Auto Zone store and they scanned the code and told me it was P0420 - bad catalytic converter.
I replaced the cat converter with an after market model, however after 3/4 months (after driving 2000 to 3000 miles), check engine light came on with the same code. The mechanic changed the cat converter and put a new (after market model). Again after 3/4 months (2000 to 3000 miles) check engine light came on again. And this time the mechanic replaced the cat converter and also oxygen sensor. Now after 4 months or so the check engine light is on the vehicle again.
The mechanic is now saying that the problem is not with the cat converter and he is saying there is a lot of abnormal deposit on the vehicle. When he scanned again he found another issue that read something like "high voltage" and this time the guy thought may be due to short circuit (per code) the fuel injector is sending high volume of fuel and this is causing excessive fuel to go into the cylinder and hence high volume of emission. I replaced the fuse box again and after another 100 miles or, the problem is reappearing.
105,000 miles on my R32, starting to get check engine light for catalytic converter. Any cheaper options to VW originals that won't harm performance?
View 1 RepliesThe check engine light on our 2005 Honda CRV (146,000 miles) came on and stayed on. After a week of driving with the light on we brought the car to the dealer to have it checked. The dealer diagosed a faulty catalytic converter given a P0402 diagnostic code and didn't think the P1078 code for the intake manifold a problem. The dealer also stated that the oxygen sensors were fine. We declined the dealers offer to replace the catalytic converter for $2,170 and the check engine light was reset. After two weeks of daily drifting and 1000 plus miles the engine light is still off. Did we actually have a problem? Why hasn't the light come on again?
View 8 RepliesI live in CA and recently my car passed the smog test, but failed inspection because the check engine light on the board was on. When the diagnostic test was done, it said there's a problem with the catalytic converter. It's so frustrating because the car's emissions are within limits. , I was thinking... Is there a way to get the catalytic converter to run cleaner without replacing it? If it can run long enough to pass the diagnostic test, my car could pass inspection.
View 3 RepliesI had my local garage do their electronic check when my check engine light came on. They said the code they got indicated a failed catalytic converter and quoted me $720.00 for a California compliant replacement, including labor. I live in Connecticut. I'd like to take a few days to get a second opinion and second quote, but the garage manager said that driving it in this condition would risk fouling the oxygen sensor, which I recently replaced for a couple hundred bucks.
Should I be concerned about fouling the oxygen sensor by continuing to drive the car? 2000 Toyota Camry...
I looked under the car and the rear attachment bolts to the converter are rusted beyond recognition. I'm tempted to try replacing it myself but it may be a bit beyond my skills.
I bought an 04 elantra a few weeks ago. The check engine light is now on and I get code P0420 listed twice with my code reader. I have replaced the downstream O2 sensor and reset the codes only for them to return again. It is my understanding that this is going to be a convertor problem. My question is that from the research I have done it looks as though this car has two converters. One at the exhaust manifold and then another in the tailpipe. Which one is going to be the most likely causing my Check engine light to come on. Or do I need to replace both converters.
View 5 RepliesMy car is in the garage, been having a bunch of issues with the check engine light. This is my current problem, Check Engine light is popping up because the catalytic converter is sending an error. However, there is nothing wrong with the converter, it keeps sending the same error. My car has been in the shop for exhaust issues and valve problems, but this has got them stumped.
View 24 RepliesHad the check engine light in the 2005 F150 (90,000 miles) come on. Got the code checked and its P0420. I know that has to do with the cat threshold levels etc. so I believe I am looking to replace the o2 sensor, if I am not mistaken.
How hard of a job is this? Ive done a decent amount of engine work and worked in a shop in high school. Just looking to see if that is the right thing to try first, replacing the sensor, before replacing the cat.
Also I know its the right bank, but if I am not mistaken there is a before and after the cat o2 sensor, which do i replace? Both?
MK4 GTi - My check engine light came on a few days ago and when I checked it, it pulled code P0420.
Just this morning, the check engine light went away.
Is this a common issue? Or should I go get it checked just in case?
I have recently had about $1620 worth of work done on my 2000 4Runner because the check engine light came on and the code was P0420.. My invoice says they replaced the exhaust pipe assembly. Now 2 weeks later the light is back on with the same code...are the 02 sensors part of the "exhaust pipe assembly" or are they now going to tell me I need a bunch (2-4) 02 sensors replaced.
View 3 RepliesMy 2005 Dodge Dokota 4.7L V8 152,000 miles has an intermittent check engine light (CEL) code P0420 ('catalylst efficiency') that turns itself off.
1) 151,000 CEL on, code P0420, checked, cleared at dealer.
2) 151,948 CEL on, code P0420, checked, cleared at dealer (Cat Conv).
3) 152,200 CEL on, code P0420, checked, cleared at local auto parts store.
4) 152,597 CEL on. No checks.
5) 152,815 CEL turned off on its own
6) 152,849 CEL on. No checks.
7) 153,137 CEL turned off on its own.
Twice in this time CEL has came on soon after a fill up from near empty.
Engine runs fine, 18-19 mpg highway.
Have seen numerous on-line reports of other possible causes:
a) base engine problems (coolant or oil) -- coolant temp sensor
b) Air inleakage -- air systems or manifold
c) Lazy front O2 sensor
d) fuel pumps
e) timing or misfire
f) what else? - (gas cap, other...)
What to check first or categories to eliminate?