hard to answer question

[turboblacksrt]

i have a s1 pcm and i do run a lot of leaded race gas, would that lead have an effect on my downstream o2 sensor? already changed upstream which looked like crap and wondering if i should changed downstream since i haved a s1, no CEL codes by the way

[turboblacksrt]

i have a nw e-cutout which at times i open/closed depending on accassion, but i run 110 race gas on occassions and every other weekend, last weekend i had half tank of leaded 110, even though i dont get a CEL will a bad downstream o2 still make car run like crap?

[turboblacksrt]

bump..

[04srt4black]

Well I know for a fact that on s2 you dont have to run the secondary O2 in the dp , you just leave it plugged up to the wires and zip tied to the side.

But im unsure what your asking ? You have no cel , and the cars running fine ?

[HCCAFan]

IIRC the mean time before failure on leaded gas is something like 25,000 miles for a good O2 sensor. You will certainly go through them faster. My question is, leaded gas shows richer on my A/F guage. Is that a false reading or is it in fact running richer?

[turboblacksrt]

nope, car runs poor i already changed upstream o2 sensor which was looking bad, i guess from all that lead crap and downstream looks just as bad, i had never changed them in the 2 yrs i had own the car and i run at track once or twice a month with a 1/4 tank of leaded race fuel, car is running poor, at times theres like a delay for 1 or 2 sec when i give it some gas but at wot its not that bad, also lately my gas mileage sucks, i changed plugs and wires so thats out of the equation