Ok so a while back my check engine light would go on when it would either be 50+ MPH or 3k RPM. So i thought the O2's are going out. I bought a pair from AM the NTK's. Got them installed the same time i got my O/R h-pipe installed, and......check engine light still turns on. Not as often but still did. So ok i thought it was my IAC/TB that were dirty. So i cleaned them out with some TB cleaner. Now check engine light goes on even more. Ran the code and it came up with the o2's reading lean on top end. Can it be just bad O2's? or can it be something else? Because the o2's are reading but i doubt its the reason it runs lean. Any suggestions? After cleaning out the IAC/TB the car seem to be less responsive throttle wise. And i didnt clean the Air filter and the MAF.