Update. I thought maybe the problem was that the car was stone cold when I left home, and I got it warmed up but not much more on the way to the emissions place. So I decided to really 'blow the cobwebs out', and try it today. Unfortunately, I could only find one diesel emissions place that was open today, near Boulder. I really can't afford to take any more time off of work to take care of it during the week-- it had to be today.
I drove it from my house in the middle of metro Denver, warmed it up carefully, then proceeded to give it about 45 minutes of 'Italian Tune-up'. Typical move is to run 2000 RPM in fifth, WOT until I need to slow down or get a ticket. I went to an under-construction industrial park and simulated drag racing. I have heard that it puts the turbo under a lot of strain to go WOT from low revs, so most of my runs were 2K to 4200 under WOT. There wasn't a whole lot of traffic on the Boulder Turnpike, so I'd slow down to about 40MPH with nobody around, and just gun it until I hit traffic, usually around 85MPH. I definitely hit sustained max boost at least twenty times on the way to the emissions place.
In Colorado, the only emissions requirement for diesels is that it have no more than 35% opacity at 40, 50, and 60 MPH under load. My readings yesterday were 48%, 41%, and 37% respectively. The tech ran the tests again, with the same results. So, how well did my 'tune ups' work? I paid $70 at the Boulder tester to find out. First test: 45%@40, 37%@50, and 33%@60. Okay. He ran the test again. 49%@40, 36%@50, and 38%@60. Fail HARD, again. So, I've spent $105 to flunk the test twice in two days. 'Italian Tune-up' didn't fix whatever's wrong with this car. The weird thing is that I was standing right behind the car for all four tests, and saw very little visible smoke. The guy right after me today has exactly the same car, down to year, nozzles, and color. His smoked like a freight train, and he PASSED!! ***?!
I'm going to read up on this here at the club, and see if I can find something to get my car to smoke less. Unfortunately, I modified mine (PP520 nozzles with low-smoke set-up), so tossing it in the dealer's lap is not an option. Argh.