rich/lean problem with 5sfe

[BlckShadow]

ever since i had a new clutch put in my 90 gt, its been throwing codes for running too rich and running too lean. i replaced the o2 sensor and rewired the harness side of the sensor and it didnt help. if anybody has had same problem or knows how to fix it please let me know. thanx

[Saggz]

Possibly vacuum leak. Did you pop off any lines and forget to connect them? Connected them incorrectly? You'd be surprised how many little problems can be caused by a leak.

[Cammoe]

So what ended up being the fix for your rich lean codes, because I've got a 92 5sfe throwing them now after replacing motor. Car runs great, lots of power, but check engine light comes on and throws 25 and 26 code for to lean and to rich. Have tried lots of things all with no luck.

-Cleaned Throttle Body (replaced gasket too)
-Tested for air/vacuum leaks (none)
-Replaced fuel pressure regulator on fuel rail
-Replaced Fuel pump and fuel filter due to low fuel pressure
-Adjusted throttle position sensor
-Checked timing (at crank, cams, and distributor)
-Cleaneed spark plugs
-Replaced upstream o2
-Replaced all vacuum lines

Please help if you can

[MR2Jedi]

Check your AFM. Maybe there's something hindering the flap.