OK so today I installed a K&N CAI on my 4.6l f150 and I realized that when I Put the truck in Park it almost sounds like it wants to shut off and my revs jump up and down a little bit, they go from 400-500 and the truck starts to make a humming noise coming from the intake i believe. Now when it is in drive the truck feels normal. I also just switched from 89 fuel rating to 87 since it is cheaper and that is what it was our truck where meant to run.

 

It was also meant to run the stock intake too. The humming or whistle is usual with intakes. Did you reset the ECU when you installed the intake? You may have also contaminated the MAF with the oiled filter, clean the MAF.

 

clean the maf, make sure you have no vacuum leaks and rest the computer

 

ok before i started to install the CAI I disconnected the battery(only the - side) (is that considered reseting the ecu). I also bought MAF cleaner and cleaned that before installing it into the K&N. The truck starts up fine and then if I put it in Drive it acts normal, but when i put in Park it struggles but then goes to normal.



is that normal?

 

I had mine struggling after I installed my CAI. It was not until after I did my exhaust system that it went back to normal. With that change my conclusion was that it was bringing in more air than it could handle with the stock exhaust system. Mine was so bad that the engine actually turned off a few times.

 

it only does it in park and according to the rev, brings down my rpms to about 5-600 in park, but when i first start it, it stays at around 8-1000

 

When you first start the truck it should be around 800-1000 and after a few seconds it will drop to 5-600.

 

after you installed the K&N, the excess of Oil in the filter maybe put some oil in the MAF. Clean the MAF again, now that you have used it for a while. maybe is dirty.

 

clean MAF and throttle body

 

How do you rest the computer? I've been having these same problems.