i have a k&n 77 series cold air intake SIDO cat less exhaust and a custom vmp performance tune and my truck is running super rich?? i get around 10 or 11 miles to the gallon... what can i do to fix this my act programmer can only do WOT air/fuel ratio. i was wondering if i get after market 02 sensors will help the computer not be confused and pump in more fuel. If you have any suggestion on what to do to stop me from running rich please help!

 

Unless you monitoring fuel trims then it will be very hard to tell if you are running rich. O2's should be replaced around the 100k mark and use motorcraft ones only. I would suggest contacting your tuner if you think you are experiencing problems.

 

You can smell the extra fuel that is not being burnt and I think that the motor now that it is flowing better thinks it need all that fuel all the time but it only needs it at high rpms. I have 98000 miles now. Are motorcraft 02 sensors the best aftermarker ones?

 

The motorcraft o2 sensors are the way to go. They are stock replacement part and work better than any aftermarket ones out there. I would contact Justin at vmp and discuss your issues.