I'm actually surprised given how "green" CA is that they don't already smog-test light-duty diesels. In many other states including mine all light-duty diesels (below 8000 lbs I think) between 2 and 40 years old have to undergo an annual exhaust opacity test. It's really not a big deal and it's very easy to pass, but it costs almost $40 which is more than the typical gas smog check.

I wouldn't worry about having to modify or abandon your light-duty diesel. Just keep on driving and worry about something real.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL