I know the same questions have already been asked. I've been searching this forum and others for about 2 weeks. So here's the story...

I've always liked Audi's, and I finally got the opportunity to purchase one. Albeit, it has high miles (109,000), it's a 2002 and has some problems. On my way home from the stealership, my CEL came on. I work for a local dealership, and had them run the code. Of course, the dreaded P0420. I know more than likely the cat needs replaced, and might as well do the O2 sensor while I'm at it. Audi dealership quoted me $1500, place I bought it wouldn't cover that. They told me if I could keep the cost of repair under $700, they'd do it. Here comes the questions. I have a local muffler shop that can do it with OEM parts for $550. Or I could buy a test pipe, and have this shop make me a custom exhaust, and I could just bill the whole thing to the stealership where I bought it. Any suggestions on this? Yes, there are local emissions testing, but no sniffer tests. I had a Sentra a couple of years ago with a high-flow cat, and I used the spark plug fouler trip, worked like a charm. Don't flame, like I said, I know this has all be asked, but I need opinions here. Is it worth it, or should I just get the cat and try to save my money later for mods? I'd love to at least have a new exhaust, this car is way too quiet for me...

 

Oh, and I almost forgot. When driving, especially at lower speeds, I tend to hear a "whomping" noise, sounds like it's coming from the rear tires. It increases with speed, but is more noticeable at lower speeds. I'm hoping it's just a tire off balance, but has anyone else had any experiences like this?

 

28 views and no one has an opinion? Come on, I know better than that..

Let me provide some additional info on the first problem. I got the CEL on the way home from the dealership. 1 week later I Sea Foamed the car, intake, crank case and gas tank. Smoked like a hooka in a frat house. Next morning, CEL was gone. Stayed off for about 5 days and came back on this past Wednesday, and it's still on. I don't notice any bad smells, the engine doing anything funny, or poor gas mileage (quite the contrary). Any ideas at all?

 

I've had the same experience buddy . What brand of tires do you have on there. Mine are Yoko Avid H4s. Annoying the hell out of me.