Well, I learned something new today: Drive Cycles ….
A couple days ago my 1997 BMW 540i failed an emissions test (for the second year in a row). Last year I had shown enough money spent on the engine to get a waiver. This year, I was a little nervous because I didn't know whether they'd give me a second waiver or not. (This vehicle is a blast to drive and a PIA to take care of or work on!!)
Well, I just got done speaking with the head of the Air Quality Testing for ADA County, my new friend Roger (I have to say that it's nice to be able to talk to the head of the department — that's one nice thing about living in a small populated state). What happened was not that I failed, but that they couldn't read my car's computer. The reason was that I have not completed a drive cycle since the last time I reset my car's computer codes (Any time I work on it, I reset the codes to see if I have fixed the problem). I figured anytime I got into the car and drove it that the computer would be on and recording normally. However, until a drive cycle is complete, none of my monitors (which are really groups of codes) are actually capable of being read. So, Roger, who said he consulted with the EPA back in 1992, said he had a good deal of insight into what constituted a drive cycle.