I have got a PO420 diagnostic code for my 2003 Hyundai Elantra, the sellsman said it was a Catalytic Convertor defective? Also gave a list of other possiabilities 2) Engine missfires or running problems (which this is not a problem) 3) Large Vacuum leak?? I have not heard any leakage and 4) Engine oil leakage into exhaust but i have not seen any smoking....So have any idea that it probley is the Catalystic Convertor...thanks Danny
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Re: PO420 code for 2003 Elantra
Catalytic Converter Failure is a common cause of a P0420 Code. 1.) I would give a few calls to some muffler shops and get a thorough exhaust inspection done. As a leaking/damaged Exhaust Manifold, Catalytic Converter, or exhaust pipe could be some of the culprits as well. If it were any of those other items your car would give you a different OBD Code. Item #2.) This is not common with a P0420 Code. With the P0420 code you should have no driveability issues. (not to say that you wouldnt in an extreme rarety) Item #3.) Again this would flag an entirely different code such as P0455 (Large Evap Emission Leak) Item#4.) Engine Oil would not even set a code. I hope this helps you out, and thank you for using FixYa!
I have a 2004 Hyundai Elantra and got a P0420 error code. A computer readout showed that it was the catalytic converter. I tried to fix the problem the usual way. First, I removed the negative battery terminal and allowed the computer to reset. That worked only a short while then the darn check engine light came back on. I then went to a friend of mine, who has a mechanic shop, and replaced the O2 sensor next to catalytic converter that worked for only a few hours. That solution worked for just a few hours and then the check engine light came back on. I live in NY where they have strict emissions test. The car was due for inspection. The warranty on the catalytic converter had expired. I was at a loss. That is until I got a devine stroke of genius.
I went to the dealership and purchased an O2 sensor for the car, one straight from the manufacturer. It seems that my friend had installed a good O2 sensor but it was an aftermarket or generic piece. Once I got the new O2 sensor, I went to the auto grave yard and asked one of the guys if he could do me the favor and replace the O2 sensor. I paid him 30 dollars and he did the job which took about 10 minutes to complete. Shortly after that I dashed to Autozone, where they are doing free dashboard comuter analysis. What do you think happened next the fellow at Autozone told me that the error code was cleared.
The check engine light has not come on since. A word of advice: Most of these components are electrical therefore if you are replacing them make sure that the negative battery terminal is disconnected. Spend the extra money and get specific parts made by the manufacturer. Shop around on line for out of state dealerships. My O2 sensor cost me $118. I have this feeling that if I would have gone to the dealership. I would have paid 10 times more. Not to say bad things about factory trained technicians but the work can be expensive. If after changing the O2 sensor after a few short hours you get the check engine light. Don't fret. Par the car, pop the hood and remove the negative battery terminal. But this time instead of removing it for 10 or 15 minutes. Leave the battery terminal disconnected for 5 to 6 hours. If you want to do it for a longer period of time, go ahead. Leave the battrery terminal disconnected overnight. This is the best computer reset. After you reconnect the battery terminal go for a 30 minute drive at 55 to 60 MPH. This should allow the computer to completely reset.
Well, I am sorry that I was too wordy but I sincerely hope that this solution helps you or anyone else that may need it.
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One of the most annoying is the persistent PO420 diagnostic code (Catalyst System ... not only shows its teeth when the catalytic converter is on the blink, but can also be ... Most, if not all, catalytic converter failures are caused by a problem or ...
Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency ... If they have failed, it is likely due to something else that caused it to fail. ... the catalytic converter is broken or failed, it may be restricting the exhaust which will ...
Code 420 is for a problem with the catalytic converter. The computer uses the O2 sensors in front of and after the cat to monitor its activity. The problem could be one of the sensors, or the cat. The system would need to be checked out to find the actual problem.
that is the code for the catalytic convertor. it is either bad or not working at optimal levels. In most cases this in not such a big deal unless you live in a state that does emission testing buy pug in and not tail pipe emissions. Most states now use a quick OBD II plug-in
test to check emissions compliance on 1996 and newer vehicles. The
plug-in test is faster, easier and cheaper to do than a loaded mode
tailpipe emissions test on a road simulator or dynamo-meter. The rules
in most states say to pass the OBD II plug-in test, the vehicle (1) must
have a fully-functional OBD II system (Check Engine lamp works and the
diagnostic connector communicated with the engine computer), that the
Check Engine light must be off and that there are no
current codes in the computer's memory. If this is the case than you're going to have to replace the converter.
po420 is catalyst system efficiency below threshold. meaning is--- could be down stream 02 sensors or a bad convertor. try buy replacing down stream sensors, hopefully this may help. ( down stream 02 sensors are between convertor and tailpipe). have a good day !!
po420--- catalist efficiency below threshold--- possible fix. a po420 means that one or more of the following has happened. the easiest thing to do, is erase code with scanner. and see if it comes back. the engine coolant tempuature sensor may not be working properly, damaged exhaust manifold, or catalytic convertor may be bad. check 02 sensor also behind convertor towards rear. its really hard to say can be anyone off above!! but check 02 sensor first it may be bad.
Fault Code Definition
Code P0422 indicates that the Bank 1 Main Catalytic Converter's
emissions efficiency has fallen below the minimum allowable limit. This
threshold is tracked by a Catalyst Monitoring Oxygen Sensor located on
or near the outlet of the Catalytic Converter.
* Check Engine Light will illuminate
* In many cases, no abnormal symptoms may be noticed
Common Problems That Trigger the P0422 Code
* Defective Catalytic Converter
* Engine misfires have damaged the Catalytic Converter
* Internal engine damage resulting in high oil consumption and/or a leaking Head gasket has damaged the Catalytic Converter
* Oxygen Sensors are replaced when the real problem is a damaged Catalyst
* Catalyst is replaced when the real problem is internal engine damage, which is producing elevated emissions levels
* Catalyst is replaced when a misfiring engine is the real problem
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Hi the code P0139 is Bank 1 sensor 2 lambda sensor fault ,possible wiring or sensor fault even if you replace the sensor you need to have the MIL lamp turned off by a Diagnostic machine,it is possible you have another fault such as poor Catalytic converter efficency giving the same fault code ,Would recomend you get the car checked and read the "live" data as the car see`s it to make an accurate diagnosis and cure