tripuhlet

Hi ... I recently got a H pipe flowmaster system put on.... A week later going down the highway , the ENGINE light came on...
Got the code read and it says its: P0420 & P0430... Which means... THE PCM HAS DETERMINED THAT THE CATALYIST SYSTEM EFFICIENCY FOR BANK 2 IS BELOW THRESHOLD FOR THE CURRENT ENGINE OPERATION...and the other one read the same but says BANK 1.... They said its because of a bad Cat Covertor.. Well suprise suprise.. I do not have one.. What do I do know.... not sure wut oxygen sensor it would be if it had one.. i see 4 sensors just like I did on my stock system.. What do you reccomend I do!?

Chopper

It sound like you will have to get MIL eliminators to fool the O2 sensors into thinking that you have cats.Or a tuner to turn the sensors off.

SilverGTV8

Yup you need some MILs, don't skimp get the good ones about 80bucks.

kubball2005

Exactly, sounds like you got an off road h-pipe and didn't get MILs. I'm surprised that if you took it to a shop they didn't try to sell it to you.

stonemonk9

i have the same code, only mines just the bank 2, also have an off road x. I have jus been driving around like that since i got it.