Hey everyone,

I am working on my brother-in-laws Endeavor and wanted to do a oil change and spark plug change. (130,000 miles)

He had a check engine light that had come on and off for sometime I was told. Said something about a misfire on a plug. Not sure which one.

So I get the Endeavor in my hands yesterday and start to change the plugs. I figured, I'd start with the front 3 plugs as they are super easy to get to.

I pull out the number 2 plug and to my surprise, my sock and the plug and covered in oil and oil is pouring out of my socket.. What the heck?

Look it up - see this is a common problem and it's a simple fix with the tube well seals. OK, order those and continue working on getting the intake off.

That itself was an 'endeavor' and finally got it off. Removed both valve covers and to my surprise was able to get the seal tubes off the valve covers without any problems.

Thought the new ones would go on the valve covers, thought I got the wrong seals, but figured out they slide on the tubes on the heads, and then the covers go one over those..

I get the thing back together and start it and smoke it pouring out of the thing. What the heck? Thinking what did I do that could cause this?

Then start thinking, wait.. the spark plug wells were filled up all the way with oil...so removing the plugs.... oil into the cylinders..

Sure enough, after a few moments the smoke goes away. Thank god!

But still missing and not running like it should.

Clear the codes with my Torque app and start it up.

I am getting this:

P0303 - Powertrain Cylinder 3 misfire detected
P0203 - Powertrain injector circuit - cylinder 3

Now, I didn't pull or clear the codes before I started working on it - but my brother-in-law says it seems to run better, just shaking at idle and in reverse. Worse than it was before.

So.. I was reading on here that many said 'Injectors don't go bad'.. but this is a 'circuit' issue according to the P0203. Is that something different?

Can anyone advise me what to do? I don't mind going back and replacing the injector, but if these 'don't go bad' and it might not fix the issue..

Is there something else I should be looking at?

Sure fun! Took me like 4 hours to get it apart, waited a day for the parts (tube seals) and then only an hour to put it together.