I wanted to know if it was necessary to have the second O2 sensor because my downpipe only has 2 holes n wanted to use one for the wide band also my second O2 sensor had been off for a while n i have had my check engine light on forever code P0421 i checked it rite before i started my turbo install n still just that code comes up just want to make sure taking second O2 sensor and putting wideband in instead wont mess anything up like running rich or anything thanks

Also if anyone can tell me what this is it could help as well



thanks for the help

 

i do not believe its needed, i accidently ripped mine off and havent been told otherwise... but im sure someone else would know for sure..

 

Truu mine has been unplugged for a while but i just put my turbo in some people r saying i need it some not RRM said i do but its just the stock plug is a ***** to reach to put it bak in lol

 

The ONLY thing the second 02 is for is to confirm the cat is operating within normal parameters it has nothing to do with engine operation

 

NIceee and since i put new exhaust in with no cats im good rite? aka im installing wideband lol thanks a lot for the help oo and will my CEL always b on or is their a way to take it off?

 

if your 5 speed, flash on evo rom onto your ecu, and disable the CEL for it.