I just bought an f150 and my uncle who owns a collision shop said i could help him but i still cant find the awnser neither can he basiclly its a 2005 f150 4x4 5.4l v8 and it has no catilac converters but thats getting changed tommorow hes putting them on and it reads o2 sensor bank 1 2 3 etc... and he knows that the o2 sensors on the truck are not installed and hes going to install that tommorow as well and the truck is running straight pipes however it runs fine on idle and it only stalls and misfires when given gas what could be wrong please help i need the awnser asap or is it what i stated above i dont know please and thank you

 

you dont say how many miles... you have to check all the tunning thing... air filter clean, fuel filter clean, spark plugs -check/replace if needed-, cops.... do you have a tuner in that truck? or the previous owner maybe had one? if so, check if doing the changes you are doing are not affecting the program. maybe it was tuned to be ran without cathalytic converters and now that you are installing that you maybe causing a problem with the tuning.

 

oops i forgot it has 118 000 miles everything is clean and i forgot to ask about tuning but im sure he got that as well ill still ask to make sure also no tuner nothing its only missing that stuff cause i bought it from the auction as a stolen veichle carfax i know thats what i get for getting an auctioned car -_-

 

Maybe because the o2s are out, the comp is not reading right, and not enough gas is being burned?

 

i dont know we will see tommorrow i guess because i didnt think it would be the o2 sensors because it sounded weird that only when you push gas that it would stall but idleing is fine

 

Punctuation and capitalization are wonderful tools when it comes to making things understandable.

I'd offer a suggestion, but I really can't understand what the problem is, because I cannot read the mass of uninterrupted text.

 

If the O2 sensors don't correct it (don't forget to remove the battery cable for about 30 seconds to reset the PCM of it's faults), then it could be bad COP's (coil over plugs). These too can set codes.

Another poor idle/poor acceleration is carbon buildup behind the throttle body plate. May want to remove that and use a good throttle body cleaner (don't use carb cleaner; the plate has a coating on it).

One last thing: when removing the battery cable to reset codes, it may take about 30 minutes of driving for the PCM to "relearn" itself, so that it for a drive and see if the idle and bogging are corrected.

 

hey thanks bucko for actually helping me for tomorrow but how about the misfire that i can feel would that be a case of the spark plugs or does that fall into what you told me

 

Mis-fire may be one (or more) bad COP's (coil over plugs, and/or the spark plugs themselves. With 118 thousand on the engine, I'd want to know if the plugs have been changed. If not, your in for some fun....those early 5.4's are a bear to change the plugs. Can be expensive if you have it done.

Read the spark plug sticky at the top of this section; you see what I mean.