I have a question. I have a 06 F150 5.4l that I just replaced the factory intake with a 4" cold air intake. I reused the Factory MAF. I drove the truck for a day or so and noticed a huge increase in horsepower and throttle response however now the Check Engine light is on and I have lost most of the power. I tried pulling a trailer and it was useless. Would barely increase any speed even withitfloored. Anyone have any ideas on what it might be? My first thought is that is might be the factory MAF. Thoughtit might not be getting as much air since it is in the middle of a 4" tube instead of a 2" tube? But just don't know. Thanks for any help or thoughts.

 

It's possible that the MAF sensor is dirty or oil from the filter (if you use this type) is clogging the sensor. Just clean the sensor with the correct cleaner (like CRC Mass Air Flow Sensor Cleaner. That should do the trick.