diagnostic codes 12 & 25

[cajunbull61]

I have an '89 GT with a/t and 169000 miles on it. It didn't pass emissions because of high nox. I'm thinking egr and timing. I pulled the codes 12 & 25. I have run a can of Seafoam thru the engine and replaced the O2 sensor. I have checked the egr and cleaned the egr vac modulator. The timing was advanced past the 15 degree mark. I hooked up the timing light and the car ran fine then the rpms went to about 500rpms then died. It restarted but it wants to idle at 500rpms. Set the timing to 10 degrees but still running the same and the check engine light stays on. Still have 12 & 25 codes. Any help or ideas will be greatly appreciated.

[Doctor J]

Code 12 is for distributor pick-up coil or its circuit.

[89CelicaGTTurbo]

code 12 is RPM signal:meanig no NE or G signal to ECU within 2 seconds after engine has been cranked. trouble areas distributor circuit, distritutor, starter signal circuit.

code 25 (in CA cars only) Air fuel Ratio Lean Malfunction: meaning when air fuel ratio feedback compensation valve is making the car too rich or lean. trobled areas are injector circuit, injectors, O2 sensor, AFM, or ignition system.

[cajunbull61]

Found the temp sensor broken in half!!! Replaced it and rechecked the timing and passed the emissions test!!!! I must have bumped the temp sensor when I was adjusting the timing. Thanks for your replies.