I'm new to this forum, what a great site for information! I've learned a ton about spark plugs and other related issues I've seen with my truck but I'm having a slightly different issue that I have not seen talked about on this site (or I haven't found it yet). I have a 05 F-150 4x4 with a 5.4 and about 130,000 miles on it. It's been a great truck but lately it's been acting up. This issue has happened six times now so I think I'm getting a good idea of the conditions that create it. The first time it happened I was driving at around 50 MPH heading toward a red light so I took my foot off the pedal. I wasn't paying too much attention to the truck but it seemed to be running fine. Well the light turned green long before I reached it and I tried to accelerate. I was still slowing down and I looked down and the tach was still at around 900 RPM (steady idle) and the yellow wrench was on. No matter what I did with the pedal it stayed at idle. I pulled off the road, turned off the car and restarted it. The light went off and everything went back to normal. About three months with by and it did it again. Yesterday it happened four times. I suspect it has something to do with the throttle position sensor but what do I need to do to verify this is the problem?
Has anyone else heard of this condition?

 

It is problaby the Throttle body itself along with the TPS. I've seen on this forum infor regarding this issue.....you can take your truck by just about any auto parts store and have them read the codes from your on board computer to verify this.

 

check the driver control modual it controls the fuel pump and is located above the spare tire

 

I borrowed a Hickok NGS MachII tester from work and pulled the codes. Looks like there was a P2104 and a P2112. I cleared the codes and this issue happened again on the way home from work. I checked and these codes appeared again. I looked them up and as expected it appears it has to do with the throttle position sensors but it is still unclear to me how to check them. Any ideas??

 

I don't think you need to check them the computer has already check them and it's saying the Throttle body is bad....it's time to replace it.

 

I would clean the TB and replace the sensor...or is that the one peice deal ??