I just installed a K&N cold air intake on my truck and the service engine light keeps coming on. I can reset it by disconnecting the battery cable but it comes back on after 20 miles. I've also had the 4 wheel drive place reset the sensor and it came back on the next day. K&N said that the sensor on that year model is overly sensitive and offered me a full refund. Should i keep driving and hope the computer relearns itself or replace it with another brand. I have gained horse power and picked mpg's with this unit but i just don't know about that service engine light. Any ideas?

 

You're probably running lean. The MAF/IAT sensor is calibrated for the stock air duct. You have either an enlarged the air duct or air leak after the MAF/IAT sensor.

 

The enlarged air duct came with the intake and I've had a installer double check for air leaks

 

Get the refund, then. It's not going to happen, "the computer relearns itself," since there's nothing for it to learn. It's programmed to raise the fuel trim to accommodate the unmetered air only up to a certain point.

 

I would assume the filter is oiled. Most likely oil got on to the Maf sensor. Try to clean it and wipe some oil out of the filter. You may need to swap the filter for one that is not oiled.