Cel 1124 & 1126

[rexcramer]

1124 1-3 and 1126 4-6 Oxygen Rich Limit

These 2 codes started last October. They were intermittent in the beginning, continuous now. The car runs as good as it ever has and the fuel mileage has stayed consistent. Generic OBD show the CAT and the OS2 not ready. I am forced to deal with it for CA smog testing/registration. The car is stock 97/Tip with 26K on it. I have had the AOS and associated oil lines X/O in January. Tubes and plugs were done at the same time.

I have searched both here and Planet 9 for answers. If I understand correctly (big if) these are the possible causes;

1. Air leak somewhere. I have used my eyes, stethoscope and propane to try and find something to no avail.
2. Oil cap leaking. It appears to be sound.
3. Gas Cap leaking. It appears to be sound.
4. Fuel pressure related, pump/pressure, filter and or injectors. I can’t test the pressure myself.
5. MAF. I have cleaned it twice.

I have hooked my OBD up to my 09 S to compare the MAF readings. I am not sure if that is applicable. The 09’s MAF response is much faster than the 97’s. And it registers higher values of lbs/s. The CAT values are also consistent from side to side on the 97. With the car running, I pulled the plug from the MAF. The idle stumbled but kept running and stabilized. I think I read somewhere that the car should stall? Mine didn’t.

What else should I be looking for/considering before I drop her off at the indie? Thank-you in advance for any suggestions.