Truck is 2001 F-150 SuperCrew/5.4, 90000 miles. My truck was running beautiful but it was time to change air filter. After chaging it I drove the truck 40 miles and all of a sudden it started missfiring, seems to be when in overdrive at around 55 MPH

 

At 90k, if they haven't been done yet, it's about time for new plugs, and possibly some cops. It wouldn't hurt to try cleaning the MAF sensor. Is it throwing a CEL?

 

What did you forget to plug in?

Regards

Jean Marc Chartier

 

It's not giving any code the check engine light isn't on. I haven't changed the plugs. I can't understand why it ran like a top one minute and after I changed the air filter it ran like ****. It does seem that something came unplugged but I haven't found it yet

 

hello everyone.....anyone ever have a clicking sound come from the left hand side from console ..around the passenger airbag?

 

Also when it starts missfiring at 55mph in overdrive, if I take it out of overdrive it's not as bad, almost not doing it at all. I'm no mechanic but I certainly have changed a few air cleaners!! I also cleaned the MAF with CRC Electronic Cleaner and it didn't seem to make a difference I didn't handle the MAF I just cleaned it where it lays.

 

i'd say it needs a tuneup with new cop's. check the plug gaps. how dirty was the old air filter?

 

I know it probably does need a tune-up, BUT it ran like a brand new vehicle just 20 minutes before I changed the filter and then it started running like ****. I don't mean to sound sarcastic but I really don't think the problem is a tune-up!!!!

 

I'm guessing I jarred something loose along that idea and I just can't put my finger on it.

 

Is it just a replacement paper air filter, or is it washable?

The reason I ask is because I have a washable filter, and the otrher day I washed it..lol
I don't think I let it dry out enough and threw it back in. The next morning I take off and the truck hicuped a couple of times. It has never done this before. I think the air filter did some dripping and that water was working it's way through the system. It's been fine since.

 

I think its probably just an odd coincidence it ran fine after installing the filter for awhile. You need new coils and plugs.

 

It is a washable K&N filter, but I took it out, cleaned it and let it dry for two days, oiled it let it sit for six hours , put it back in. While I was waiting the two days for it to dry I put the original one in temporarily and that's when it started all the fuss. The original one is practically new so I figured it would be alright for two days!!

 

the oil from the K&N may have contaminated the maf. or maybe your engine can now breathe but isnt getting all the fuel it needs to run right. when was the fuel filter last changed?

 

*double post*

 

It may be possible that the mass air sensor needs a cleaning? Perhaps it has oil build up from the K&N. I'd start there since it's much easier to clean the MAF than it is to replace COPS.
The timing seems iffy considering it only happened after you put the paper filter in, but who knows?
How often do you clean and oil the filter?