I have been driving the car since new. 110k miles. I have been doing my own tuning E30. 21PSI mediocre timing. Just did oil and new factory plugs less than a week ago.

I was 2 hrs from home pulled out of a parking lot and the car went nuts. Crazy fuel trims. Popping etc.

P0031 Heater Control Circuit Low B1S1
P0130 02 Sensor circuit B1S1
P0131 02 Circuit Low Voltage B1S1

Somehow I was able to get it home. The STFT was working properly no codes all the way home. Never had a hiccup. Right when I got home I filled up, I was watching HPTuners, STFT stopped working car threw the same codes again.

Replaced the front 02 sensor with GM 12589380. Reset computer. Start back up.

P0030 Heater Control Circuit B1S1
P064D Internal control Module 02 Sensor Processor

STFT not working. Car runs fine besides that. Switched back to GMS1 and no different. I changed the EXH fuse, no change.

The P064D has me very confused.

New battery?
New Bank 2 sensor?
Different fuse?
Sensor Wiring?
Try new sensor?
Bad ECU?

 

Check the wiring and trace it.
Sounds like a damaged plug or wire

 

I'm pretty bad with electrical. But I do tend to agree it's likely a wiring issue though.

Is there any way it could be the rear sensor or rear sensor wiring? I was gonna change it anyway and look at the wiring for it. I figured it would throw a code if that's what it was.

 

B1s1 is always gonna be the primary

 

The harness is like right on the turbo if you do not clip it back or the clips break. Heat can melt them and the pins comes lose.

 

Yeah I just replaced the primary last night with the factory part. Pretty sure I had the right part.

 

Know the procedure to check the voltage on the harness? I do have a volt meter.

 

Pulled the harness back. It was resting on the head.

 

Is that wire broken or exposed copper? Kinda blurry, if so, that's ur problem

 

Due to the heat, some of the wires are discolored, yellowed is what I would call it. Most of them have some kind of scrapes. None are majorly exposed.

I really have no electrical experience so i will have to take it to the dealer. No idea how much it will cost me. But I need it back.

I have a question for you guys. I have been driving the car. It is a little rough to start in the morning for obvious reasons, but when warm the car drives fine. The AFR sticks at 14.7.

Is it safe to drive out of boost to work and back? I have been and it drives fine. Taking it in soon.

 

Safe to drive out of boost? Why wouldn't it be? U don't drive while boosting all the time do u? Cause that's just abusive

 

I'm only asking because the primary 02 is not functioning at all.

I know the car commands lamda of 1 except in close to WOT modes.

 

Just a follow up.

Rewired the front 02 sensor. No luck

ECU had to be replaced. I suspect the 02 sensor harness grounded out and destroyed the pin on the ECU for the 02 sensor.