I have an 02 ZX2 thats been running pretty crummy. The gas mileage has gone down, the car’s been running rough and i have 2 OBD codes, P0135 and P1451. Has anyone else had any similar problems?? Help please.

O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1). The cheap solution is to wiggle it and make sure it’s not loose.

Has no discription.

I’ve alreday replace both O2 sensors for the P0135 code. The P1451 code is “Evaporative Emission Control System Vent Control Circuit” I’ve replaced the gas cap, charcoal canister, and the controler relay for the charcoal canister. All with no help. :?

I went through today and reset the codes with a reader, and 10 min. later they were back. I have no idea whats going on.

More work today. i reset the codes again and tested the relay, and the hookups to the charcoal canister. everything looks good, but the codes come back in under 5 min.