Bad 02 Sensor?

[Generation X]

Quick question guys:

If you have a bad upstream 02 sensor on a 2g 4g63T, will the ecu automatically put the car in limp mode, therefore throwing any tuning out the window?

Thanks for any help.

 

[Denji]

Quick question guys:

If you have a bad upstream 02 sensor on a 2g 4g63T, will the ecu automatically put the car in limp mode, therefore throwing any tuning out the window?

Thanks for any help.

Well.. i had an o2 sensor go bad and my a/f guage was reading only lean, meaning my car was constantly trying to compensate with rich, so i would be inclined to say that the general answer is not necessarily limp mode (as i didnt run a check engine code) but definitely would mess up tuning.

Also, i couldnt really tell any driveablilty issues, but then again when i got my car dynoed, it runs way rich anyhow.