No throttle/accelerator pedal


Registered User
Aug 25, 2013
Reaction score
United States
Hi guys just wanted to share something that happened to me, hopefully itll help someone out.

Short version- Unplug the exhaust back pressure sensor. Driver side above the exhaust manifold, below the degas bottle. Follow the silver tube coming out of #2 exhaust up to the pressure sensor.

Long version-

Truck is an 05 F250 I bought about 8 months ago and have had great luck with it. I put a coolant filter, Rotella ELC coolant, FoMoCo oil and fuel filters on it and have been changing oil every 6k miles with Rotella T6. 20k miles and no issues towing and cruising. Recently my starter went out which was an easy fix. Bullydog GT tuner with pyro. I also like to "feed her the dinner" and max the boost gauge @ ~24psi every couple hundred miles to clear out the carbon on the valves, vgt components, etc. Who knows if it helps...

I took an 1800 mile trip and everything was running great. Driving on the highway a little wrench popped up on the dash. The wife looked it up in the manual to be something to do with the electronic throttle. I figured no biggie and it could wait the 100 miles to our destination. About 2 minutes later the truck started mildly hiccuping. Cruise control still worked ok. Over the next 10 minutes it got worse until I had zero throttle input. Cruise worked ok still. Foot to the floor and the engine didnt respond whatsoever. Luckily I rolled into a gas station. The truck started and idled fine. I noted the codes on my BullyDog GT and reset them because I wasnt sure what were new/old.

Not sure which ones are relevant:

On the BullyDog I was viewing "Throttle" which would either be 0 or pinned wide open at 127. It was late, my brain was fried, and I spent a good while looking for a TPS...on a diesel. After I grew a brain I began unplugging sensors around the oil filter which I had some idea what they were for. EGR valve, coolant temp, etc. Nothing worked. I took the AirAid intake off and saw the exhaust back pressure sensor. Unplugged it and I could see the live throttle inputs change on the Bullydog, key on engine off.
When I get home I'll take the tube out, clean it, research how to test the sensor and wiring for a short. For now hopefully it'll drive 2200 miles with it unplugged.

My take-
Either the sensor was completely ruined or somehow the wires got chaffed which fed the computer too much voltage causing it to shut down and go into "limp home" ie. idle-no throttle mode to prevent damage to itself. I believe the same thing could happen to any one of the other sensors that the PCM monitors like the coolant temp or maybe EGR or VGT, mine just happened to be the backpressure gauge.

Again just trying to save someone from sitting on the side of the road for 4 hours pulling their hair out wishing they did a 12v swap 4 months ago while frantically searching google and their engine bay.
Last edited: