Help please. I changed the coil, spark plug, even the fuel injector and it is still misfiring. It's a 02 f150. What else can I do or try?

 

Check the compression.

What engine?
How many miles?

 

5.4 and 150xxx

 

What codes is it giving you?

 

Cylinder 7 misfire detected

 

Results of a compression test?

When we ask for codes, please post the numeric "P" code. Thanks.

 

Codes P0307 and no haven't ran a compression test yet.

 

Matt, code set is the results of slow rotation time on that cylinder as measured by the crank sensor.
'
If anything that can cause 'slower rotation time' such as spark plug, coil, low or no fuel or
low compression will be detected as a misfire.
This is the only way the computer can detect it.
Good luck.

 

Update tested and started the truck and now it's reading P0300 and P0307 and there's a rotten smell from the exhaust but it has most of its full power. Could the catalyc converter be starting to go? Besides that anything else I could check?

 

You have to pay attention to the code descriptions.
300 is a 'random' misfire detected.
307 is still cylinder 7. Os a heater hose above it leaking coolant and dripping on #7?
A cat issue will affect all the cylinders on that bank,.

The cats have their own codes assigned. 420 through 429 plus a look with a Scanner at their performance by watching the rear Ox Sensor outputs..
What happened to the compression test?
There could be coolant leaking into the cylinder causing a misfire.
You need to look at all possibilities until something shows up.
Good luck.

 

Am late to the table. But, bluegrass is probably right. Cross over tube gasket will leak coolant right into#7 cylinder. Pull the cop on#7 and look for moisture. Shine a flashlight in it. When I pulled my #7 plug out at lat tune up, the plug was moist around the rim. It's a known problem apparently. But, hard to pick up on due to location. And usually you'll see some effervescence around there as well for indication it is in fact leaking. Sorry for the late chime in.

 

I have an '01, 5 yrs "New to me."
Late for him maybe w his "02 in '17, maybe, but valuable to we "new" 10th gen guys... and.I THANK YOU on our behalf. My *barely* leaking head gasket took down some cyl in bank 1. It all held 17 psi forever... and it took 4 years, multiple diagnosticians and hydro-lock to discern the true issue, and melted a plastic intake manifold, as the issue EVER so gradually got worse. ALL this info is GOLD !!! 2001 for US, is NOW. Keep those cards and letters coming ! 285K and freshening-up the 4x4 150 - 5.4. Yes, wish my SCab was a 7700. Don't need a 250. Near 20 mpg at 65. Parks in SF ok.w.a.real driver, too TOO easy to find myself at 90-100 in between SF & Sacto CA! No offense to my Great BCA Tranny UpBuild, love it, but dang... If only it was a STICK!!!