One easy swap-out is the O2 sensor, That tends to do the trick. However, I had two bag plug wires that caused a very rich reading during emissions. The way we ended up findind it was with a timing light. It just so happened that plug wire #1 was firing intermittantly. We thought at first it was the timing gun but other guns had the same "malfunction." Upon testing the other plug wires, #5 also suffered the same problem. I only had about 10,000 miles on the car since the last tuneup but I figured if I was going in I might as well do plugs, cap, and rotor. That was the trick. Everything came down to within acceptable levels. Good luck, and let us know the outcome. Matt Olans VIN 16816 www.az-d.org The Arizona DeLorean Club --- In dmcnews@xxxxxxxxxxxxxxx, "vin4258" <vin4258@xxxx> wrote: > > Wonderful news in that vin 4258 failed its emissions idle test. > Readings at 686 RPM were 289 for HC and 4.25 for CO% when 220 and 1.2 > are legal limits respectively. I have read through my tech service > manual and it says that I don't want to adjust the idle mixture screws > since they are factory set and don't need subsequent adjustment. So, > where should I start- is this easy as an air filter change (it > probably needs one) or is it the cold start valve or thermotime > switch, or a new direction completely. BTW the same readings were 72 > HC and .8 CO% at the high speed test (2378 RPM) which passed. > > Any thoughts? > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/