hey guys i have an 02 f150 with a 4.6 and when im accelerating i can hear almost like a back fire and popping almost like a misfire sometimes the harder u romp on it the better it gets other times it hesitates and shakes truck on the highway i can set the cruise at 110km/h and it does the same thing until i take it off ive checked my codes the only thing that pops up is the code for my o2 sensor cause of having no catelytic converters, i changed the spark plugs and 2 of the boots that were cracked didnt help also i had truck running and i disconnected one injector at a time to see if i had a bad coil on one cylinder didnt tell me nothing what else could cause this? the truck has a cold air intake,throttle body spacer and dual exhaust it did it before i put the the cold air and tb spacer on any help is greatly appreciated. thanks

 

Well missfire is correct maybe a coil or plug or worst case valves

 

it hooked it up to a code reader again and it said misfire cylinder 8 so i pulled that coil out checked plug and took the number 1 coil out put it on cylinder 8 and put the 8 one on the 1 to see if would throw a misfire for that cylinder to rule out the coil and now ive got no misfire code and the truck still runs bad. I was getting a code po115, and po155 i have no idea what they are, would a fuel filter cause a problem like this? again thanks for all the help

 

also another question would an exhaust leak at the manifold cause any of these symptoms? also could fuel filter be a problem

 

A code po115 is your engine coolant temp sensor is it hard to start dies backfires smokes black?

 

Not hard Start doesn't die or smoke black

 

Try the coolant temp sensor that's your one code. The other will be caused by it.

 

Maybe the malfing coolant temp sensor is putting the truck into " save the engine, limp home condition."

 

Where do I find this coolant sensor? And also the code misfire on 8 is back

 

It on the inside of the left front head. Its hard to get to I know when I put new motor in my truck i forgot to put it in