For about a month now, I have been routinely clearing codes in my 2001 Jetta. Every time, I get P0606 (PCM Processor Fault). Sometimes, I get a P0420, which is odd because I've replaced the O2 sensor 4 times since I bought the car used in 2003. When I clear the codes, it takes about a week for them to come back, but sometimes it throws the P0420, and it ALWAYS throws P0606.
I'm a student.... I'm broker than broke. I understand that dealerships charge upwards of $100 just to check the PCM, which is more than I can afford. I've also read that there are a lot of times when its not actually the PCM, and dealers will just throw parts at it until its fixed. I really need some help determining what else it could possibly be... Any suggestions anyone?