$90 gas cap or $6 gas cap??

St. Louis has emissions testing. Its "supposed to keep the air clean". Whatever-it has much more the appearance of a way to get more money. I really wish they'd just tack the testing fee onto our registration fee and leave it alone, versus making people jump through hoops to get their car tested. However, here's a tip that recent experience has taught us, if your car, which appears to be performing fine and isn't trailing out black smoke, fails emissions testing, and they offer to tell you WHY it failed for a mere $90 diagnostic cap, tell them to shove the diagnostic machine up their ass and go directly to an auto parts store and get a new $6 gas cap. That what we did and since they re-test it for free, we went back and voila! the car passed. How insanely easy and cheap. In fact, I might just say if your vehicle has 70K miles on, hell, spring for the gas cap BEFORE you take it to emissions....save yourself the second test.