my '89 240 will be due for emissions inspection next month. It has about 208,000miles on it, and in the 3 years I've owned it, has had no problem passing the emissions. I changed the cat converter about 2 years ago, the O2 sensor a year or so ago, and the plugs, distributor cap and rotor about a month ago. The air filter probably has 4000 miles on it, so I might put a new one on just for the inspection. It runs ok, but I've been thinking about putting in a bottle of one of the fuel system additives that are "guaranteed" to help pass emissions tests. My thought is that even if it was going to pass anyway, it might not hurt to clean it out.... so my questions are: 1. are they generally safe to use? 2. does the bottle do more than the </body> "injector cleaner"? I'm guessing that they are mostly "snake oil", but if they do no harm and MIGHT do some good, perhaps it's worth throwing a bottle in the system occasionally..... Any thoughts????