1996 S-10 2.2L with 160K. Two years ago, the vehicle did not pass smog, and failed miserably ("gross polluter" in CA). It ended up being a stuck thermostat. Last year, it passed fine. Two months ago, it just did not pass, although not bad. I replaced the oil, filter, PCV, air filter, plugs, wires, upflow & downflow O2 sensors, disconnected the battery, fixed a small leak where the exhaust flex pipe joins the exhaust manifold. Ran it through what I was a "cycle", brought it in and they said not all the computers have reset. Huh??? Cat seems fine.

So, any ideas what I am dealing with here? If the computer or computers are not resetting, is there a fuse that might be involved and possibly needing replacement? Why is my GOOD running truck, with NO odor from exhaust, not passing smog this time? Any thought or direction here would be greatly appreciated.

 

When you disconnect the battery it resets all the drive monitors that the inspection place checks. You will need to drive it until monitors have all set again. The inspection places are wise to clearing codes by disconnecting the battery... It takes several drive cycles to get all the monitors to set. Up to a week of driving..

 

what part of the test failed?


did they tell you which monitor did not complete?