Ok well my car was at my mechanics for like two weeks to try and get the CEL fixed so I could get it inspected. He basically tried everything short of just replacing parts in hopes that it would cure the problem. My question is, could bad O2 sensors because causing the computer to read both banks rich if they were on their way out? He monitored the voltages and they read correctly and he said that he saw that they were at least trying to lean everything out, but apparently it just isn't enough.

I am not sure what else to do at this point but these stupid codes are going to drive me to sell the car. We also already replaced the MAF. Any input is appreciated. Thanks

2001 Volvo S40-Perrin MBC@ 11psi, EST intake, 35% tint, still slow