I noticed my o2 sensor before the cat wire had been cut! Some retard must have done this before i bought my car. I know this is a noob question but exactly how will no o2 sensor effect my car??? i just bought a new NTK o2 sensor , but haven't installed it yet.

 

There are too many variables to list of what the primary, and secondary O2's analyze for an unmodified factory ECU. Basically, the primary O2 sensor reads "unfiltered" readings while the secondary O2 sensor reads "filtered" information, and sends that to your stock ECU. Left as you have stated in the current condition your ECU will eventually run a "limp-mode" setting sacrificing efficiency in every aspect imaginable compared to a normal factory ECU program running under factory spec'd conditions. While throwing a CEL (check engine light), which is very annoying, and costly... fuel economy, horsepower, and wear-item life will suffer, such as spark plugs, and surprising enough, O2 sensors.

My advice:

install the O2 sensor you purchased for the purpose of maintaining factory spec'd running conditions. Or, have your car reverted to OBD-1 specs via a tuned OBD-1 ECU, such as a "chipped" OBD-1 P28, P30 and/or P72 ECUs (modified to allow ECU program changes), and a jumper harness. Any tuner can modify many other ECUs to run as the ones I've listed. If you feel like contacting me I can explain what other ECUs can be used.

If its a "track-only" car you can remove the cat, but I suspect you should already be running OBD-1. But given the original question, I doubt it. I merely state this for people who search this subject in the future.

In closing, OBD-1 ecu tuning will give you much more freedom for tuning of any aftermarket part you install. It will benefit even a stock C5, but this is highly illegal in states such as California. But please maintain local laws concerning this, and all tuning (wink-wink) if it is a street driven car. But you will lose the great diagnosis or "reading" capabilities which go along with an OBD-2A/b equipped chassis.

Please read up on C.A.R.B info for more information, and what states concern their emissions laws based on C.A.R.B. laws. I hope the info that I know helps.


Good luck, my friend.

 

Thanks a lot! By the way I have a chipped P30 ECU.