2001 Pontiac Sunfire, automatic trans, runs smooth; HOWEVER, occasionally the TRAC OFF light will illuminate and Sunfire won't accelerate past approx. 10mph - high RPMs as if maybe it's not upshifting like it should??? Turn off, restart, and runs fine until the next time... Check Engine Light on, previously only threw 2 codes P0221 (TPS) and P0440 (EVAP); cleaned throttle body, now only throwing code P0440. Please help, and thanks in advance!
(Woops, trying to edit title...)
I would replace the TPS sensor, and the IAT sensor. Both mess with the transmission a lot. I would also check the ground to the TPS and IAT sensors. Either one can make the trac off light come on.
The PO440 shouldn't mess / cause your conditions.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Thanks for your reply, -MD- Enforcer! Should it still be throwing a code for TPS if that needs to be replaced? The P0221 code has been gone for days after cleaning the throttle body. Related: Should IAT throw a code if there's an issue there?
(Unrelated: Can a mod edit the original title to reflect RPM instead of RPS?)
IAT will not throw a code.
TPS may not throw a code, but may not be showing 0-100% if you can log the sensor.
IAT normally fail, and the car thinks it is VERY cold out.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
