I have a 2000 VW Passat 1.8L Turbo wagon. Over the last year I have spent approx $2900 in repairs (ABS computer module, alternator, timing belt, water pump, and various air pump system issues). The check emissions light has come on several times over the last year, and always relating to the air pump system. I have had the hoses/pipes replaced, the system cleaned, and most recently spent $500 to have the EGR/air pump valve replaced ($200 parts, $300 labor). Always there has been a rough idle, which has never really been addressed by my mechanic. After the EGR valve replacement in July, two weeks later the check emissions light came on again. I took it back to the mechanic, they said the codes were the same as before, they tested the air pump and it was working fine. (The car had gotten a significantly noisier). They cleared the codes and said to call them if the light came back on. A week later the light came back on. I called my mechanic and they said they could clear the codes and post on an online mechanics forum to see if anyone had any answers, and that I could come in, they’d read the codes and clear the computer and we’d go from there, but that they didn’t believe anything was really wrong with the car. I drove that way for a week, and the light suddenly went off. The car is much noisier at this point, and I start smelling exhaust. I figured, muffler issue. Once I started smelling exhaust in the cabin, I took it to Midas for a diagnostic. No hole in the muffler or exhaust, but the tech found a hole in the EGR valve adaptor (the part which connects directly below to the EGR valve). If the mechanic had caught this when replacing the valve (which, who knows, maybe didn’t need to be replaced at all), the labor costs would’ve been the same. Now I’m looking at another $400 (parts+labor) to have the adaptor replaced. I could throw some epoxy on the hole as a temporary fix, but I don’t want it to blow out and then bang around and wreck another part of my engine. I also don’t know if it’s too rusty to be welded, but it is in a kind of precarious place. At this point I can’t drive it anymore b/c the hole is big enough that CO poisoning is a real issue. I am so angry at my mechanic at this point that I don’t know what to do.
Any advice for how to deal with or complain to my mechanic, or how to fix the problem without replacing the part?