O2 sensor not reading
Thread Starter
Heel & Toe
Joined: Dec 2021
Posts: 17
Likes: 0
O2 sensor not reading
Hello, i currently just installed corsa headers on my c7, while also getting a tune. After getting it all installed and programmed the car was throwing codes for the b2 s1 O2. just tore the header off and checked the wires that i could see, also replaced the O2 with another new one and checked the gasket and everything was fine. Still throwing the code. After watching the vehicle it shows the B2 S1 is stuck at 1278mV and not moving at all. Any idea or help with what to do or look at next.
Team Owner
Joined: Jul 2004
Posts: 28,369
Likes: 3,258
From: Hartford WI
The O2 sensor plug is male. IOW there are 4 prongs sticking out and going into the female end of the harness. Are you SURE those are all where they should be? You are saying it gets 1.278 Volts which should be way too high. Disconnect the plug and see what happens. If you have a voltage change, lets look at another sensor. If you don't, we might need to see if the harness is somehow screwed up.
Thread Starter
Heel & Toe
Joined: Dec 2021
Posts: 17
Likes: 0
I've looked at the harness and even replaced the O2 just in case it was faulty. while watching the vehicle the B1S1 was running great. I was told to check for burned wires but found none. is there a way i can test the O2 wires from under the hood? its not easy getting to the O2 plug once the header is bolted back up and everything is zip tied. I'm getting codes P0050, P0051, P0155 
Race Director
Joined: Mar 2001
Posts: 19,918
Likes: 6,712
From: Bonneville Salt Flats
Did you chemically clean and carefully inspect all electrical connections that were mucked with when doing whatever work was done? My father worked for a GM dealer back in the day when the earliest semblance of computers were just appearing and he said that was probably the most common source of problems, not counting faulty GM factory parts. Just sayin'... All the best. 
