bigelboe wrote:No O2 sensor is not causing those problems, you can safely disconnect it and the car works fine. Idle might be slightly richer than normal. Even if it calls an error code 1 (I think thats the 02 one) the car runs fine and idles smooth.
The only thing it does is tune your idle and low load mixtures a bit better to save fuel, has no effect on full throttle operation.
Replaced the o2 sensor.
We also swapped the black boxes over between cars, as we did it we chucked some contact cleaner down the valve.
This seems to have fixed it, neither car is overboosting now.
Thanks for the help guys!
Now on to the next problem.