my '00 f-150 with the 5.4 has been idling a little rough after warmed up, in drive, like when I'm sitting at a light. I recently replaced plugs with bosch platinums. I haven't noticed any lack of power or stutters whiles driving, like a misfire. the enginge light isn't on, so I don't think it's a COP problem (I didn't replace them with the plugs, which I suppose should have been done- I have 111,000 + miles...) I also have a K&N FIP Kit. I kinda thinking maybe MAF? Should I just clean it with electrical parts cleaner? any special procedures? how finicky are these sensors?

 

The sensor is tough and pretty durable. I clean mine by taking the MAF section off and spraying the crap out of the small port with electronic parts cleaner. I then take a damp cloth and clean the rest of the inside of any grime. I set it out until I know it's thoroughly dry then re-assemble. Job done.

For your uneven idle, check your IAC (idle air control) solenoid. It is that small box off the back of your throttle body that faces the firewall. I believe it is four 8mm bolts that hold that baby on there. Once you pull those bolts off (don't lose them down the back) you can disconnect the plug and pull the solenoid off. Be careful when you remove it as the gasket will be brittle and you might break it. If you do, run down to Autozone and grab another one (or you can do what I did, spend $1.50 for a small square of gasket material, trace your old one and cut a new one). It will probably be dirty as hell. Clean out what you can with a towel then spray the crap out of it with the electronic parts cleaner you used for the MAF. This solenoid controls the idle air flow to the engine when there is no throttle input. This is a common cause of poor idle as it gets dirty easy and nobody cleans it.

As a side note, my 5.4's brief history of spark plugs: hated Bosch, tolerated Autolite and loved Motorcraft.

Hope this helps.

 

My truck is foing the same thing Thanks Brian. Go Navy I was stationed in San Diego(North Island) in 1992-1994

 

I rplaced the IAC valve about a year ago... still hums a little at cold start up. maybe I'll clean that out too... maybe I need to re torque the sucker. thanks. Go Army, beat Navy.... 7+ years so far, Airborne, All the Way!

 

I have the same issues but have already cleaned the MAF and replaced the IAC. I thought maybe COP's are the culprit although it seems unlikely. The TPS could be to blame but good luck getting it off. I plan on replacing all the COP's and pulling the IAC again to check it.