Is it possible for the O2 sensors to be bad, and the ECM doesn't throw a code?

I have a 96 Z28, and the thing burns gas like there's no tomorrow. Runs like crap (surges) at part-throttle.

It feels like it's in "open loop" all the time. I have a OBD2 scanner, and it doesn't recognize the VIN number, and says there are no codes stored.

I'm wondering if the dope who owned this thing before me messed with the ECM and screwed it up.

I ordered a new set of O2 sensors anyway...

Any takers?

Thanks....

 

You can turn off any DTC code you want if you have a laptop and Tunercats.

 

Shoebox?? Injuneer???

Need some help here guys!!!!!!

 

O2s don't always throw codes. It just depends on what is going on. What you need is live data analysis to see what is going on.