Sorry for the long post, it’s my first one on this site. My truck is a 2006 Extended cab 4x4 (XLT) with the 4.6L engine with 149,000 miles. My truck has become my leisure vehicle, so it has not seen a bunch of miles lately. Probably less than 8,000 last year. Here’s a couple of changes to the truck recently, I had new tires were installed on Thursday last week (can’t imagine it has anything to do with it). The tank of gas I put in it on Friday was non-Ethanol which I used to run all the time but 2yrs ago the price gap between E and Non-E gas got to $.40 and I couldn’t justify the price difference with as little as I drive it.


I haven’t had many engine related issues (knock on wood). Saturday night driving home I noticed the engine stumble or hiccup while driving down the interstate (70mph), not accelerating just steady speed. I thought not much of it, “maybe it was just a bump”. Ten minutes later I’m on a less traveled county rd, driving a steady speed (60mph) and the engine just cuts out. No miss or hiccup, didn’t bog down or sputter, just dead/gone. I did notice the security light flashed right when the engine stalled, coincidence? I’m not sure. Oh I forgot to mention it was 3 degrees outside and I had my two little kids!!


I pulled over placed it in park, and it turned the key, it fired right up. On down the road I go watching for any other signs. I notice the fuel gauge is at ¼ tank, and before it died it was at ½ tank? Weird, pulled over looked for leaking fuel, nothing. Kept going, headed for home, no more issues (20 miles). Never had a MIL (CEL) light or anything. Haven’t pulled codes but I plan to check that (guessing there aren’t any).


So here’s a couple of things I’ve been meaning to get checked out, fuel economy has dropped a bunch. Probably close to 3 mpg. Truck seems sluggish, have to make it downshift on most hills. These have been going on for the last few months.


I looked at several posts and different sites for possible fixes but I’m not sure any of them match my symptoms. Then again maybe they are not related. Any suggestions on things to check? Electrical? Throttle Position Sensor? Fuel Pressure? Fuel Filter (it probably needs it anyway)?


Thanks!!
-Josh

 

Get your cats and the rest of the exhaust system checked for blockage and excessive backpressure at a muffler shop. Change the fuel filter, put a couple bottles of Techron in the tank and fill it with good quality fresh gas.

 

I had it happen on my 2005. It was the throttle position sensor. On my engine, the TPS was integral to the throttle body, so the whole throttle body had to be replaced as a unit.

Mine started it did it ONCE, within a week, I literally could not drive it 10 miles without it happening. It happened several times in heavy traffic on the interstate, not safe at all.

Anyway, it was a pretty easy fix, and I was able to find one used, it was $78.00 total. The one I got was off of a 2007, but it was the same part. Bolted it up and boom, never happened again, got 3 more years out of it until I sold it in August.

Also, a failed o2 sensor will give you similar symptoms (loss of power, bad fuel mileage) and will kill the cats, but you should also be getting a check engine light and ODB2 codes.

Plugged cats alone will not cause it to stall, you will notice massive loss of power and bad fuel mileage though...

 

The fact that your fuel gauge changed (vacuum crushed fuel tank)strikes me that you could have a purge valve issue. This video is for the 2009 and on, but you also have a similar type of valve. The cold may have had some effect on having it happen:

https://www.youtube.com/watch?v=S6dsQoq73aE\

2005 Purge Valve.

Another problem could be your Fuel pump driver module. Lots of problems with this as well:

https://www.f150online.com/forums/ar...placement.html

FPDM