hello all, new guy here, I have a 2005 TT Quattro, 3.2, owned it for only 2 months and I really love this car, because of gas prices here in Pennsylvania being $3 a gallon I was running cheaper fuel, and now I have the p0420 code and a p0430 code , now that's with using a generic scan tool, my question is can I use an after market oem cat? say like a borla high flow? everyone tells me audi's have issues with after market parts, relly need some feed back, I don't know jack about audi's so this is all new to me. Thank you

 

for got to mention it only has 64,000 miles on it