Hello every one my name is canaan i am new to the forum and this is my first post so please go easy on me jk. i drive a 2008 ford f150 xlt 4.6 v8 185000 miles. over the past few weeks my truck has started to miss fire when i am driving normal , going up hills , giving it some gas, ect and has flashed a #4 cylinder miss fire. so i did what you think you would do , change the coil and spark plug to no success. so i unplugged my battery and cleared the code to see if it would pop back up but it has not,(truck is still misfiring) and when i turn my ac at idle my truck surges down to 200 rmp and almost dies before returning back to normal idle. any help is needed i am stuck and do not know what else it could be. ia also have cleaned my maf sensor as well. thank you have a good day

 

 

Yea it probably wouldm't hurt to change all the plugs and coils, and always use Ford/Motorcraft ignition parts.

 

all the sparkplus that are in except the one a changed are the original spark plugs

 

[QUOTE=CANAAN;6142344]all the sparkplus that are in except the one a changed are the original spark plug

You definitely need to change the plugs.

 

 

185K miles on one set of plugs... doubt it. Either way put a fresh set of Motorcraft plugs in her along which some new boots and springs.