[bdcochran]

Bllorights has it nailed.
1. modern technology (check engine light) has not relieved this old timer of periodic eyeballing the fluid levels, checking for leaks, listening for unusual sounds.
2. an auto parts store, Midas Muffler and my mechanic will run a scan for free.
3. usually, the problem is an unscrewed gas cap or the need to replace the gas cap. have replaced mine twice on a 16 year old car.
4. sometimes, if it is the evaporative system, you can run the car at high speed for an hour and put in a cleaner like Guaranteed to Pass Smog and it works. worked twice this last year. light on again. will try to pass smog. if unsuccessful, run the diagnostics again. option 1 - use a machine to clean the fuel injectors without removing. i have saved some good ones from when i had to replace bad ones about 4 years ago. option 2 - unbolt the catalytic converter and clean it in the sink, but have the mechanic do it. why? Because when i replaced three motor mounts this year, i knew, given the car age, there would be problems, was correct, and a machine shop had to help my mechanic in the effort.

 

[bdcochran]

Update. I finally waited until I failed smog testing to run a smoke test on the lines. Replaced three hoses. Passed. AZmercedes was right. Could be a zillion things, usually related to the smog. Happy that I didn't have to go beyond what used to be called an Italian tuneup plus shoving chemicals in the gas tank to burn out carbon deposits.

My state rules are simple. If you don't pass smog and don't own a historic vehicle. there is no limit on what you must pay to pass smog. Missed a bullet this time.