engine light

[woody146]

hi i have a 2003 gmc seirra z71 and i got new exhuast put on a while back dual from the heads to a single mangaflow muffler then out to dual agian and the put in those o2 simulators and i have got the changed more then once because my engine light stays on all the time even after i clear the dtcs it is saying my o2 sensors are failed does any body know what the hell to do lol i have took it to many exhaust shops and everyone says that its good

[woody146]

can anybody at all help

[JennaBear]

Have you pulled the code? Which code are you getting?

[woody146]

i dont remember the exact code but its the front and back o2 sensors ( maybe i have to put simulators in the front by the heads to instead of just the cat ones)

[JennaBear]

NO NO! Those are vital for closed loop fuel control. Can you get the exact codes?

[woody146]

ya give me two mintues

[woody146]

po137
po141
bo229
po157
po161