Took my 2001 Prius in to get emissions and safety inspected for the first time in Pennsylvania. The car "failed" emissions, although there was no CEL on. Coincidentally, I replace the battery a couple days ago (the old one was DEAD). It was suggested to me (by a friend in California) that the new battery may be causing the fail since the internal diagnostics haven't had enough of a history to adequately judge whether the car is up to snuff. Does this sound likely? If so -- is there any way around it (other than waiting until it establishes enough of a history)? The inspection place I took it to seemed to have had no experience with hybrid cars (it's western Pennsylvania). They suggested doing a "drive cycle" prior to having it re-inspected (although the specific list of drive cycle activities were pulled from a 2001 Camry list since they couldn't find one for the Prius). Does it make sense that *that* might fix the problem? The car was tested warm (had been driven at mostly freeway speeds for about 30 miles prior to the test, then driven the same speeds/distance again after its first failure and before being re-tested). Any help is much appreciated and apologies in advance for posting a G1 question here. Thanks, bk412
Your friend is correct. When the 12v battery is disconnected, the computers get reset in all cars (this is not a hybrid issue) and all of the emission data is erased. The emission tests require that the computers have data stored from multiple trips to allow a PASS. You just need to drive the car for a few days to populate the data and then take the test again. I takes about 5 full trip cycles (Off and cool down, restart, drive and warm up) to populate the data. JeffD
