1998 Toyota Sienna with 209K miles recently needed its emissions tested. When i took the vehicle into get tested it passed the emissions portion but failed the test because of the check engine light. Took the van in to get an O2 sensor replaced and check engine light was turned off and everything appeared OK.
When taking the van into get tested again I was informed that in order to replace the sensor the mechanic must have reset the electrical system (or something along those lines) and that the emissions couldnt be tested because of this. According to the emissions tested I would need to reset each of the vehicles drive cycles before it could be properly tested. After attempting to reset them all one afternoon I took it back in later that week to get it retested but they still said that they werent reset and couldnt identify which ones I needed to target and that the only advice they could give me was "Drive around until the check engine light turns on then drive until it turns off again"
This was about two weeks ago and havent seen the check engine light come on or anything other siginificant indicators. My issue with this is that I need to get the emissions passed ASAP and the fact that imperfect science that is reseting drive cycles is really putting a kink in the those plans.
Any advice on what to do would be greatly appreciated.