i bought a 2000 f150 5.4 lariat 2wd five days ago. it was stumblinng and missing at idle and lacked power when driving it. i took it to the local oriellys and had them pull the code since the service engine soon light is on. it came back with the code for cylinder 4 missfire. i replaced the coilpack and plug and it improved but is still missing just a little. the service light is still on. took it back to have code pulled again this morning and got the code for ignition coil e. what could be the issue now since the oriellys did not know what ignition coil e is?

 

What are the exact codes? Problems like this with cylinder 4 are frequently due to the heater hose above it having a pin hole leak. Always have them write down the exact code. Then bring it here.

 

if i remember right i think it was po355 ignition coil e. i will go again and check it adn if i got it wrong i will post the correct one. someone told me to check the injectors cuz it will cause it to throw a code for a coil if one is not working properly. thanks for the reply. new to owning a ford. all ive ever had is chevys but the ford was only 3000 so i figured it would be a good buy.

 

Thats cylinder 5 and injectors on that engine rarely fail. sounds more likely to me you having coils/plugs fail. Tune up time. Get yourself a whole set of coils go to e-bay and buy a set. Get the best ones you can afford but like anything you get what you pay for. motorcraft are the best. Do the plugs. use dielectric grease on the boots. Torque the plugs to 28 lbs. again Motorcraft are the safe bet.
how many miles on it? plugs should be done by 100k miles..

 

I just bought it 5 days ago. the motor has 145000 and the body has 217000. it has motorcraft plugs in it. all the coil are workin cuz I can un plug them one ata time and the motor changes everytime. thanks for he advice. will hit up ebay when I get paid on th 30th

 

They can still fire and all. intermittent misfires are the way they go.. same with the plugs. They get old and just cant do it anymore..

 

thanks for the advice. another question... the previous owner took the cats off. I've done it to chevys before w no problems. but will thia affect these modular engines any in how 8t runs cuz I'm fixin to order high flow cats as well for it.

 

They wont pass emissions with out them thats for sure. I wouldnt remove them and yes depending on what all the PO did to make the CEL stay out the missing cats can be an issue.

 

I dnt have to worry bout emissions since I live in oklahoma. we dnt have inspections here. but I will be puttin cats back on it. right now it has true duals with dumped flowmasters. it would sound good if it was runnin right.thanks for the help. will keep u updated after I change all plugs and coils.

 

I had a miss fire on cylinder 8 before it threw a code. It was the coil pack.

Once I replaced it I noticed the main problem was gone, but it still ran a little rough and would fall on it's face at wide open throttle.

It was a spark plug on bank 1 that was going out, but not bad enough to code.

So the moral of this story? A coil pack can go bad without fully going out. So can a spark plug.

 

thanks. plan on changin coils and plugs as well as put high flow cats back on it.

 

That should do the trick..

 

sorry I hadn't been online n a while.got my plugs changed finally amd no more codes and it runnin great. thanks for the help and advice