2001 Ford F250 - Feels held back

F250 seems to be held back when in neutral downhill and has feeling of same when in D on flat. Engine is missing a lot at idle and below 1700 rpm when in gear.

Why are you in neutral rolling downhill?

The F250 could be sold in 6 or 7 or more engine and transmission and driveline configurations. Wanna clue us in on what your trucks has? How many miles on it? Is the check engine light on? For how long? Explain what you mean by “held back”?

Answer these questions and we’ll try and help.

Definitly feels like ‘held back’ as though the emergency brake were slightly engaged…it is not…nor are brakes. Downhill in N should accelerate quickly on the hill descent but did not pickup speed quickly just slowly and felt ‘held back’. The transmission
fluid looks lightly red

not brown in any way and is when checked warm in the zone as should be. Radiator filled to proper level with 50/50 mix. Engine oil checks all good.

Yesterday was 90+ degree day very humid and problem did not reveal until had driven at 70 mph approx. 30 miles. No check engine warning. All engine monitors of temp, pressures, amps etc. as normal at all times. Hit a hard rain front on the final 7 miles
of the trip and think the rough run and held back feeling disappeared to a great degree. Lot of water constantly misting of the trans during that 4 or 5 minutes for sure…and maybe cooled things a bit.

While thinking back a bit about 5 weeks ago…on a 140 mile RT experienced a very very hot passenger floorboard at turn of transmission tunnel to foot fall about 18 inches forward of rearmost seat set. Inspected upon arrival home and could find no shields
missing on exhaust or anything amiss. Engine had been running rough most of trip and to keep revs higher (where engine smoothed) had kept Overdrive OFF and most of cruising was at 50 mph max for the 65 miles home that produced the hot floorboard. Made the
same trip once a week or so later and had no hot floorboard. Think it was a bit cooler day… upper 70’s…than the hot floorboard day when the temp was in the low to mid 80’s.

Also remember in 2015 when towing my 12,000 lb. 5th wheel in Albuquerque NM area transmission started some shifting issue that lasted about half way to Santa Fe. Never another problem rest of the way back to Illinois that trip nor since until latest symptoms.

Appreciate you help.

Note my engine is V10 SD 4wd and am running on highways in 2wd of course.

Asked 5 questions, you answered 3 2/3rds. You defined “held back” and told me this was a V10 4wd leaving me to assume this had an automatic transmission.

How about the other?

How many miles on it?

I’ll add one more… Has the gas mileage taken a drop recently?

Based on what you wrote, I’d say your catalytic convertor is plugged. It is acting like a Jake Brake when the truck rolls downhill. It is easy enough to check.

175K miles

Automatic Transmission

No bangs of whinning sounds…just a clicking while she warms up …not more than 5 min in town…had the ticking for 11 years…but always go away with a few minutes running.

Gas mileage has dropped maybe two or three miles per Gal. …so say around 11 to 12 not towing.

Easy to check CATConv…I’m all ears!

OK further reinforces my thoughts on the cat. You can remove the upstream 02 sensor and install a pressure gauge in it. Leave the O2 sensor attached, just tie it up out of the way.

The pressure gauge needs a long hose so you can read it while driving - duct tape it to the windshield. You’ll need some adapters to screw it into the O2 sensor threaded bung. Something like this:

You might be able to borrow it for free from the auto parts store.

Rev it up to 2500, like the gauge face says and watch for the pressure. Should read 1-2.5 psi max Any more than that and the cat is clogged. Use a cheaper aftermarket replacement cat as long as you are not in California. Cali smog police insist upon factory replacements (or certified replacements).

Sounds easy enough…I’ll checkitee checkit before I wreckitee wreckit!

Thank you Mustangman