The worst problem to diagnos in any car is a 'driveabilty' problem. The computer can tell you that a sensor is malfunctioning, but nothing about whatever's downstream of it. I had an '88 CRX with this very same problem and it was the coil. Car would run great at first, but after warm-up, it would stutter and buck and miss all over the place. There's a simple way to check every piece in the system. A shop should know how to perform these to find the exact problem before they ever order a part. That's why you pay them that much. Otherwise, they're doing it exactly the way an idiot kid would in his back yard - keep changing out parts until it's fixed. With that coil problem I had, you could test the coil cold and it showed fine. When it heated up, that's when it would act up. The coil (or coils packs) can be tough or impossible to find with a voltmeter. I don't know what the fuck they were doing at the Cats. IMHO I wouldn't worry too much about them blocking your phone number. I would block theirs and probably call channel six, too. This shit pisses me off. If you're a doctor or a lawyer, you have a liscense to print money. You don't if your a shop. I worked at a dealership where the service writer's jobs were to pad the invoices as much as possible. I worked in parts, by the cashier, and everyday some poor person would be lead in by the service writer in tears asking, "How can this be so much?". I've only found one shop that does it like I do in this town and that's Clintonville Auto Repair. But then I don't look for shops. I'm real sorry you had all these problems, man.