HPI_Savage25

So we have a 1997 F150 with the 4.6 with 140k miles on it. For a while it had an EGR code. I pulled the throttle body off and cleaned the EGR ports up as they were completely clogged and put a new EGR valve on. Solved the problem for the check engine light. Anyways the truck runs like complete crap. Has no power what so ever. This truck use to get up and go even at 45-55 and now if you floor it is lucky to even rev up a few hundred. Gas mileage is crap also (not that these got good mileage to begin with though). We use this truck for pulling a trailer a lot and with it running like this it is really hitting the wallet.

Oh we also replaced the spark plugs and the wires. Thinking a coil pack but if it was a coil pack going bad it should throw a misfire code I would think

pickupsrule

Does it idle rough? You may have crossed plug wires. Check the plug wire firing order for correctness and also make sure all of them are fitting properly and locked down good. I have seen big engines with several bad plugs run smoothly at idle, so you could have some bad new plugs also. Could be fuel injectors, add some concentrated fuel injector cleaner to the gas.
If you are sure it is not that, I would go back and reverse everything I did and see what might be wrong. If it wasn't doing it before you did the fixes, then the fixes probably caused it.

Anythingmuddy!!!

Maybe your cats could be clogged happened to my truck wouldnt get any power, started to over heat, so i just went and got a new exhaust system no cats straight to a glasspack havent had any problems since.

scott516

Cut the cats off before it costs you an engine! That happened to me. Mine started missing, replaced plugs, wires, even injectors, ran good for about a week then overheated and was too late. After a phone call to a friend in Detroit, come to find out that some 4.6's has a defect in #1 plug threads that allows it to loosen, in turn putting fuel in the cats stopping them almost solid! Only problem is you'll have a 50/50 chance the O2 sensors will cause engine light to come on. They can be faked out with some re-wiring, if your good at that, which can be found in these forums.
Good luck!
Side note, my friend told me that if the temp gauge pegs it's most likely too late, cause Ford's gauges warn you too late for aluminum heads!

97SlowWhite

catalytic converters

Tonelocs47

Can you hear a ticking or low whistling/blowing when you give it gas? Could be you have a leak somewhere in the egr tube or exhaust and are losing pressure which makes you lose torque, hp and mpg, could also be a clogged cat