dwarf717

Our 05 4l v6 has 42000 kms on it. It's in nice shape. Every once in a while, usually within the first 10 minutes or so of driving after starting in the morning, and after a good and proper warm up, the car will hesitate momentarily, while at a steady speed, and at around 2000 rpm or so. After the car has been driven for a while, this problem is not present, and the car works perfect. On a couple of occasions, while my wife is on her way to work the car has began hesitating, bucking, the CEL lights up, and the car goes into limp mode. Is there anything common to this problem which I could check for?

JCON

Sounds like a loose hose to me. Possibly a vacuum line. Do you have an intake on it? Have you been able to retrieve any codes?

dwarf717

Haven't looked into it yet. No intake mods, but I believe it has a different muffler on it. Single exit exhaust, but it sure does sound nice. I have an OBD 2 code reader for my 98 F150. Is it the same reader, or is this car now OBD 3? When you shut the car off, and re-start it the CEL is off, and the car runs normal again...so far.

lundefinedl

Could be the throttle body. When I bought my 05 v6 with 30k miles, the engine started to randomly cut out while driving. This would usually send it into limp home mode with a CEL. I took it back to where I bought it, they pulled the code and said that it needed a new throttle body. They replaced the throttle body for free and the problem was solved.

Nuke

Before going to any expense, there are the simple things worth trying:

1. Clean the TB
2. Clean the MAF
3. Replace the fuel filter

I'm pretty sure there are HowTo's for all 3 in the 2005-2011 main forum stickies. The dirty TB is frequently a driveability culprit.

dwarf717

Will look into you suggestions nuke. Thanks. Not happy to hear about a tb replacement... She just got the car for Christmas

dwarf717

can't find any info on how to clean anything. Only changing fuel filter

Nuke

Here are a few links I found with a quick search:
https://mustangforums.com/forum/gt-s...ttle-body.html

https://mustangforums.com/forum/gt-s...eleration.html

I'd clean the TB first and if that doesn't help, then the MAF. Then go from there, if necessary.

dwarf717

I haven't had the time to look at the car yet, but it has been OK till today. This morning the the "wrench" light came on, plus the "engine" light as well. She shut the car off for about 5 min., and restarted it. The wrench light went off, but the engine light stayed on. It has been only the wrench light that has been coming on until now. I find it's only on extra cold, snowy days that this problem has been occurring. Coincidence?

up_yours_7

Had the exact same is in my 05 and turns out it was only the tps (throttle position sensor) not the entire throttle body like I was told. It's a cheap part and easy to do yourself mine has ran great for 40k miles now and I'm at 101,000 miles.