lithium15

I just test drove another 2001 s4, completely stock and it seemed to pull harder than my car which is stage 2. I know my post 02 sensors in my piggie pipes are bad and have been meaning to get them replaced, but would that cause my car to really seem that slow?

lithium15

P.S i get full 17 psi boost with giac chip

AudiS4guy - NorCal

i'd check for codes...

lithium15

only codes i have are the two bad 02 sensor codes

RKA

Have you checked for boost leaks (they won't necessarily throw a code).

lithium15

Test car was at dealer... completely stock, not sure what version of giac i have

AudiS4guy - NorCal

you could be getting those codes from not relocating the o2 sensors. Did you get them from piggy?

lithium15

i have not checked for boost leaks, i do not have a air compresor

RKA

If the codes are related to Sensor 1 on either bank, get that addressed. That will throw off your air/fuel ratios and make the car run like crap. Next, pressure test the system. Use a bicycle pump if you have to.

UseTheS4ce

I had a bad 02 sensor but it was pre-cat, B1S1, but it did affect performance dramatically.