Just bought a 2002 Z28 with 5.7 with CEL showing. Friend scanned the engine which indicated bad 02 sensor. View from bottom shows front sensors stock, midpipes seems to be missing Cats and rear sensors have sims plugged into harness (one was not blinking - I swapped sides DS to PS to verify if problem is harness or sims and is the sims). MY QUESTION IS: since I don't know the brand of sims, should I (a) try to replace with just one generic sims, (b) order two new sims, or (c) can the computer be recoded to delete the rear sensors since their are no cats in the exhaust system. OR - Am I just in deep DO DO

 

Most of the early "sims" were made by Casper Electronics. But about a year ago, the Feds cracked down on Casper, fined them $70,000 and forced them to stop making sims. You might find some on eBay. I doubt that the brand will make any difference. They either emulate the correct switching and voltage swings expected from the after-cat O2 sensors or they don't.

The PCM can be programmed to eliminate the after-cat sensors.

 

Thanks for the info Injuneer, looks like the best long term fix is reprogram the PCM vice expense of going back to stock system. I swapped my boat even up for this car because I figured it would be easier to sell the car in these hard times, probably still is, just not with a CEL showing. My literacy factor with cars is limited to OK to drive, but don't touch the *****. Sorry, just rambling.. Thanks again for the help.