So I have a 1997 F150 with a 4.6L Windsor. The past few weeks it's been running slightly sluggish. i run regular unleaded. the whole ignition system has just been replaced. it feels like its starved for fuel and my milage is very bad between 4 to 5 mpg. new fuel filter also. anyone else have this problem?

 

4 to 5 mpg holy heck what kinda tires are you running? do you have any mods done to it like air intake , pipes , tuner anything like that. and did you put back in a factory ignition system? also do you have a check engine light on? if you do go to advance and they will pull the codes for free or auto zone does this also

 

im running 33 inch bfg A/T's on factory wheels. modded my air box. flowmaster with a turndown im not sure about the plugs and wires. i didnt have the time to do it myself so i sent it to the shop. o2 sensors are bad.. fixin that on friday

 

i wonder if the used motocraft plugs i know these trucks dont like anything but them

 

another thing they might have opened the gap to far , or your airfilter could be cloged , the fuel filter inside the tank could be cloged up starving it of fuel

 

yea ive heard the motorcraft plugs will only work. so i guess im guna check plug brand and gap. start from there lol

 

also have you cleaned you MAF? And what kind mod did you do to the air box

 

same thing as yours except with an airaid filter

 

Have you noticed any excessive heat coming from the engine bay that is not registering on the coolant temp gauge in the dash? If it seems like there is a lot of heat under the hood, more than what seems normal, your cats could be plugged. Usually the cats being plugged creates lousy gas mileage, sluggish running, and heat under the hood but the gauge will show normal temp. If nothing else, take it by a local exhaust shop and have them checked.

 

you know, ive been noticing that distinctive plugged cat smell. ya know?? i may chop em off and throw the flowmaster back on and see how it sounds lol