2002 toyota camry 3.0, code p0430? converter inefficiency bank 2 . only code . Fist tech replaced O2 sensor 1 and the cat on that bank. It was clearly melted. it came back with the same code in a week. and again cat was melted. Second tech thinks is a misfire burning the cats down.But can't see any misfires on the scanner. so now I'm involved, Not working on cars as much as diesels.Spark plugs white. I look at the data and see the MAF sensor is reading 1.92 gps at idle . I told them the MAF sensor is bad. O2 sensor read different from bank 1 and 2. could other bank be bad to. looked at SI couldn't find much.
Last edited by tech1diesel (1/14/2012 1:31 AM)
Did you replace the converter with an aftermarket converter that was cheaper than the factory original?
It is known that low priced converters are not as efficient as the factor original and can melt under normal operating conditions.
The mechanic needs to monitor the oxygen sensors for their proper operations. One way to check the sensors is by a scope and or scanner.
The front oxygen sensor will fluctuate faster than the down stream sensor; this shows the proper efficiency of the converter. If the upstream oxygen sensor and the downstream oxygen sensor fluctuate the same this shows the catalytic converter inefficiency. The cause can be a rich fuel mixture caused by a bad fuel pressure regulator, leaking fuel infector, leak in the exhaust system before the converter or cylinder misfire.
If the engine checks out to have a rich mixture then one of the first things to check would be the fuel pressure.
Check for an exhaust leak. If there is an exhaust leak the oxygen sensors sense higher oxygen and dump more fuel into the engine to compensate for the so called lean mixture it really doesn't have. This can burn out a catalytic converter.
Try these few suggestions and get back to me when you can. We can go on from there.
The cat was from Toyota ,not aftermarket, after replacing the cat again checked for o2 leak in the exhaust system. none found, fuel trim still out of parameters, MAF still at 1.9 GPS, Replaced MAF sensor and now reads 3.8 GPS at idle , now the fuel trim is reading -0.03 on both banks. After test drive long-term fuel trim around 0. the car was released. Is their a good scanner out their for all foreign cars? ours work it called IQ scan. but nothing like the tech 2 or the ford IDS. Thanks for the help.
Last edited by tech1diesel (1/19/2012 12:51 AM)
month later, no more problem
Thanks for the update, keep us posted if anything changes.