Low RPM hesitation/sputter

[S197Coupe]

05 GT 5spd 48,5XX miles is hesitating, sputtering at low rpm, normal driving, under a load between gears. No codes pull up when scanning and no CEL. Seems to idle fine and WOT seems fine.

Symptom Description: 4th gear 45mph into a long turn lane with green light. Down shift to 3rd blinker on, slowing down shift to 2nd enter intersection look for on coming traffic and ease back into throttle *hesitation-sputter* a little more gas it goes away, 3rd gear shift * hesitation-sputter* a little more gas it goes away, same thing in 4th gear. I have yet to notice this *hesitation-sputter* in 1st gear and it is a random thing, it does not do this every time.
Things I've tried before the plug swap: Changed fuel filter, cleaned throttle body and MAF sensor.

Engine/Exhaust MODs: Steeda UDP, Pypes O/R H-Pipe (both have been installed over a year) Brenspeed SCT2 canned tunes been running 89 and 93 tunes for over a year.

Engine bay needs cleaning so it’s not something wet. I’ve changed the two piece plugs for one piece plugs (proper gap) a few days ago thinking that might solve the issue but it changed nothing.

This *hesitation-sputter* came out of nowhere I haven’t changed location, gas, driving habits, nothing.

It’s driving me crazy driving it like this, any thoughts or ideas?

Thanks

 

[S197Coupe]

Well after some reading I’m beginning to lean toward this being more of a fuel/throttle issue than a spark issue. I don’t believe it’s a COPs related issue for a couple of reasons.
1. The sputtering is intermittent car ran like hell yesterday morning on the way to work but ran great this morning.
2. There are no codes or CEL which from my reading I should see on a bad coil or misfiring cylinder. –correct me if I’m wrong.

I have some injector cleaner in the tank now, maybe it’s a clogged injector and more than likely will next try a throttle position sensor from the dealer to see if that helps.

Feel like I’m grabbing at straws now. Other ideas or suggestions are welcome.

 

[S197Coupe]

Ran great on the way home tonight. We'll see how she does in the morning.

 

[S197Coupe]

Surprisingly a TPS seems to have solved my low RPM sputter. Car is running great again.
Price on this Motorcraft part ranged from $104.00 to $46.00. Shop around if ever in need of one.

 

[evolucion311]

I can't believe nobody replied to this thread.

I'm having similar issues, search for my username for posts for help.

 

[ski]

The IP discovered one possible cause.