gordon1991

Hey i just put on a zzp downpipe with cat. Few weeks after i start getting Engine light. Ran Hp tuners to see that the dtc ECM P0420- Catalyst System Low Efficiency (SES). Was wondering if i should just disable it or is it my oxygen sensor? Any thoughts would be appreciated. Thanks

SprChrg4Life

iTrader: (1)

you have a high flow cat with the downpipe, so it won't be as efficient as your stock cat hence the code. Unless you plan on ditching the downpipe and going back to stock, most people delete/disable the code from popping up the SES light. Your O2 sensor is telling your PCM to throw the light on. if it could talk, it'd say "hey dude, where's the O2 we're supposed to be seeing? I think your cat isn't working as it should" and well... it's right. Use HPTuners to tell that stupid p0420 to stfu