i have a 1990 toyota pickup reg.cab 5 speed 22re motor my check engine light came on and it started to idlea very rough and sometimes stall out allong with poorgas milage 8 MPG. it turned out to be because of my O2 sensor i unpluged it and my truck ran like normal except for very poor gas milage 11 mpg. when i got the truck a few weeks ago it was getting around 17 or 18MPG.so i installed a new O2 sensor and when i pluged it back in it started right away with rough idle and really bad gas milage. any ideas of what it could be?

 

Did you reset the ECU when you installed the new O2 sensor?

 

no i didnt. what do i have to do to reset set the ECU?

 

Pull the EFI fuse under hood and also pull the negative battery cable at the same time.

 

ok thanks i will give that a try.

 

once you do, start it and let it idle for 10-15 minutes.

 

hey thanks a bunch CappyKD resetting the computer after plugging in the new O2 sensor fixed the problem. getting normal gas milage now