no power in engine

[MedicMoe]

Hello everybody
I have an 01 Expedition with a 5.4 motor with a 192,000 miles
in the morning when I start the truck I can drive it no problem but later on after it's warmed up for a while if I mash the gas pedal it actually bogs down and wants to die. it'll idle and I can depress the gas pedal maybe a centimeter it'll pick up speed but anything more than a centimeter and it will start dying. I already replaced all the plugs and wires last month at a hundred and ninety thousand. right now no codes show up on the computer, so where do you think I should look first? Clogged cats? Vacuum leak? Ive done the obvious tests, but am i no means an expert.

 

[MedicMoe]

so I cleaned the airfilter, looks good, cleaned off the 2 sensors in the intake hose (ambient temp) i think, and also sprayed cleaner in the throttle body. i think it helped a little but i dont think it fixed the problem.

 

[stamp11127]

Could be caused by a number of things. I would look at fuel pressure, egr valve / passages and cat temp

 

[MikeA]

Ive done the obvious tests,

What obvious tests would they be?

The more detailed a problem and what you tested helps.

 

[MedicMoe]

Cleaned both sensors in the intake, and sprayed the throttle body. Ive glanced over the engine, and see or hear no obvious beoken loose vacuum lines. The cats dont make a rattling noise. But it seems to be heat realated. Like the ambient temp is above 85. All the guages apear to be in the normal range.

 

[MikeA]

You are going to need a ohm/volt meter to run some tests.

TPS
http://easyautodiagnostics.com/ford/4.6L-5.4L/tps-diagnostic-tests-1

MAF
http://easyautodiagnostics.com/ford/4.6L-5.4L/maf-sensor-tests-1

EGR
http://easyautodiagnostics.com/ford/4.6L-5.4L/how-to-test-the-egr-system-1

You will either find the problem or eliminate these from the list.

 

[MedicMoe]

Thanks MikeA I'll check that out.

 

[ddeloge]

Sounds like a clogged CAT. Does the cat converter get red hot?

 

[rjdelp7]

Do you have a check engine light. If you do, scan with a OBD reader. Sounds like a bad TPS(throttle position sensor). No check light, could be a fuel filter or pump.

 

[MedicMoe]

the cats dont make excess noise, and I've tested the sensors as described by MikeA. I bought MAF cleaner and sprayed it twice. no change. this morning I drove the truck no problems for over an hour all around vegas ( freeway and city streets), came home, and went out again to do more errands. the second trip out, the truck started acting up ( I can't depress the gas pedal more than 1 cm, if i do, the motor begins to bog down.) I'm really stumped! Thank you all for the help still no check engine light on the dash, and when i plug in my code reder, it says no codes.