94 GT runs like crap...have EEC test codes

[jrr28]

Guys,

Please help me out. My 94 GT is running terribly. Stumbles over itself under WOT, not great in routine driving either. I just ran an EEC reader and it came up with codes for "HEGO (HO2S) sensor fault/always lean," both with the engine running and from the memory.

I do have an offroad H-pipe. I don't just want to replace the O2 sensors if it is throwing the codes because of the cats being gone. What should I do!?

I have also had some periodic white smoke from the exhaust that I have not been able to track the cause of. Any ideas?

Thanks,
Jeff

 

[jrichker]

What were the exact numerical codes?

An offroad H pipe will not affect O2 sensor performance unless the O2 sensors are too far away from the exhaust ports.

 

[jrr28]

What were the exact numerical codes?

An offroad H pipe will not affect O2 sensor performance unless the O2 sensors are too far away from the exhaust ports.

The codes were 176C, 136R. These were the only codes that came up (other than showing a problem in cylinder 8, which I know to be a slightly under-performing ignition wire which is going to be replaced tomorrow).

 

[BlownFiveLiter]

Moved to 94-95 Tech.

 

[desertcox05]

just did a ck of codes on all data pro 136 and 176 both say "lack of heated o2 sensor, lean bank 2". IMO you need to ck wiring on the o2 sensors for shorts or the sensor is bad itself. i'm not sure which side is bank 1 or bank 2.

 

[SR86]

I'm throwing this out, often gets overlooked on HEGO threads, An Always lean condition can be caused by vac leaks as well..car is getting un-metered air, and is not adjusting for it. Is the car running excessively rich?

you can test a HEGO by seeing if it's switching, from low (near zero) to high, (near 1 Volt)[or the other way around i can't recall, the value should change though] when you have someone spray some fuel into the air intake stream..