Help! Check engine light was on for some time when I had filler neck and cap replaced. Computer sensors did not re-set until 501 mile mark, when light came on again. Checking the web, I find that some who appear to have knowledge of problem say it could be hoses, sensors, valves, or evap canister–the charcoal canister.
Mechanic who did original smoke test and recommended replacement of filler tube wants to replace evap canister without checking anything else. I feel he has dollar signs in his eyes. Another mechanic is ready to do another diagnostic, but that will cost additional money.
Question: what should I do? At wits end, and car needed to pass inspection 2 days ago.