My car is backfiring at every shift over 3,000RPM and throwing a code 42 all of the time. Testing the throttle position sensor showed it was bad, and I removed it entirely to drive over to the junkyard to get a new (used) TPS. Strangely enough, the backfiring went away completely and the car ran great *without* the TPS.
The new TPS checked out fine, giving resistance from zero to infinity, and I adjusted it to read zero resistance at idle and infinity when the throttle was barely hit.
The strange thing is: the 42 code is still there and the backfiring is back! WTF! Its odd that no sensor is better than a working sensor.
Throttle Position Sensor and Backfiring
Moderators: Helpinators, Moderators
Re: Throttle Position Sensor and Backfiring
Did you check the TPS wiring to the ECU to make sure it's good?
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
Re: Throttle Position Sensor and Backfiring
Hell, that was obvious, even for meLegacy777 wrote:Did you check the TPS wiring to the ECU to make sure it's good?

After I posted I checked the oxygen sensor and that appeared to be way off of spec, putting out .01 volts instead of .1.2 volts.
Thanks!