changed 02 sensor, plugs and wires still got ses light ?

[johnnunez29]

this truck is driving me nuts! i changed all the plugs and cables, iridium plugs and changed the sensor! before the cat but my truck is still getting the po420 code. im confused as hell truck is no longer boggy at idle but code re popped up. anyone know what else it can be? where to look? thanks

 

[yukondoit]

Did you clear the code? Thats usually the way to get rid of the code. If it comes back after you clear it, then there might be another problem.

 

[mason313]

exaust leak or maybe the cats could be clogged

 

[domin8]

Did you clear the code? Thats usually the way to get rid of the code. If it comes back after you clear it, then there might be another problem.

Try starting here. Disconnect battery for at least 5 minutes.

 

[johnnunez29]

Try starting here. Disconnect battery for at least 5 minutes.

i took it to autozone and they cleared the code for me. then it rode for almost a hole day no light then bam! lol. cant be a misfire but can be an exhaust leak or maybe bad cats or even oil in exhaust ... does or has anyone had this issue?

 

[Rivieraracing]

i took it to autozone and they cleared the code for me. then it rode for almost a hole day no light then bam! lol. cant be a misfire but can be an exhaust leak or maybe bad cats or even oil in exhaust ... does or has anyone had this issue?

Is it the same code?

 

[johnnunez29]

Is it the same code?

same exact code. its po420 now my boy at work told me these trucks have 2 o2 sensors before the cat, but at autozone they only show 1 before and 3 after?

 

[SunlitComet]

They have two per cylinder bank so for total of four. One before and after each converter on your vehicle. Your specific code says the left cylinder bank converter is not doing it cleaning job chemically speaking. A dAmaged sensor, bad converter(which is what the code is for) or screwy pcm can cause this code.

http://www.obd-codes.com/p0420

 

[johnnunez29]

They have two per cylinder bank so for total of four. One before and after each converter on your vehicle. Your specific code says the left cylinder bank converter is not doing it cleaning job chemically speaking. A dAmaged sensor, bad converter(which is what the code is for) or screwy pcm can cause this code.

http://www.obd-codes.com/p0420

i had seen this and went through it. how do i test cats? i changed the driver side top o2 sensor and all plugs. seemed fine til yesterday afternoon. and whats a pcm? thanks btw

 

[scrtcell]

Had the exact same problem your cat on the drivers side is bad once you replace that all your troubles will go away...