I have a miss in 2003 5.4L. It comes and goes. Changed plugs and fuel filter but now it says it is lean cyl#2 last time it was misfire cyl#4 Can anyone please help. im just a nail driver

 

Never heard of that code before ? What's the #'s

 

Welcome. Per above, the #'s are needed. Could be a bank 2 lean code?

 

one code was 0302 didnt see the other just saw cyl#2 lean. now mine says codes P1000, P0171, P 0302, P0316

 

I thought you had it for a minute - But, I guess not

 

What Spark plugs are you running . Has the motor been wet recently? PO304 is common - was your heater core lines leaking over the top of #4 when you had that problem. Those lines can leak very little and be hard to detect . They can leak enough to cause a problem for #4

PO302/PO316 -How many miles on the motor?

Pretend the other codes do not exist for now and find out whats going on with #2 . It's easy enough to work on.. Do a visual check for any moisture , chaffed wires , the obvious..

If nothings apparent , pull it and check the boot condition and spark plug as well..

Post your findings.

 

90,000 miles on motor everything is in good condition no leaks, the boot is good, brand new bosch platinum plugs, i changed plugs 500 miles ago and used plenty of dielec grease and made sure the boots seated well. The last time i had this problem it was cyl# 4. when I drive it now it has surges of clearing up, then misses start to clear then misses. there is no certain rpm range this occurs. sometimes it clears up at1800 rpm sometimes 2500. It has been 3 months since this started. every time i can save enough to take to a dealer for them to diagnose it will stop and the check engine light goes off. I am a construction worker and this truck has been worked HARD! I have never had one single problem before this. I always maintain my vehichles top notch, very rarely miss any maintenance since they are my bread and butter. It also seems to relate to the weather, most times when it starts missing the weather goes from sunny and warm to cold and rainy, being in mississippi that can mean 70deg to 20deg. there have been a few times it missed when there were no weather changes n by the way thanks for the help!

 

I'm a construction worker as well . I don't have to use my truck for work , but I see people that do and they end up running the hell out them in know time.. Unless they happen to have a 3/4 ton Ford diesel - they last forever

Yea My 5.4L has 234,000 on it - great motors , awesome trucks

Heres what you want to do and you'll be glad you did, trust me ... Head over to Global Automotive and purchase a set of 8 COP (coils) Their only $85 (that's for all eight) Save this link for future reference. I've know this guy(Kevin) for awhile and he just expanded big time . He has quality parts and he doesn't charge an arm and a leg.. Many people on this site have benefited from his low prices _He purchases most if not all his parts from the same suppliers the dealerships do..

http://cgi.ebay.com/ebaymotors/NEW-I...mZ180206219134

You need to get rid of the plugs your using , their the worst possible for these modular motors. Specially the 5.4L - This motor is picky about plugs. So you need to install factory OEM Motorcraft plugs - They must be Motorcraft if you want longevity and performance or just to run right . There is two other options as far as plugs that work good . They are Denso's and NGK . That's your choices if you want her to run right.

That's all you have do for a healthy ignition system. Replacing all COP's at the same time w/ good plugs makes a big difference - Specially with your mileage..

Good Luck

 

Thanks, You are a life saver my man.