I own an '02 with 145000 miles on it. My check engine light came on. I took it to Ford, and they said I was getting a lean code on the passenger side. When they found the problem, they told me they thought it was an intake leak due to a failed gasket or cracked intake. (They found the leak by carb cleaner near the back of the intake and noticed a jump in the reading of the oxygen sensor.)

I picked up the truck and decided to save money and do the work myself.

When I tore the truck down, I noticed that there was a lot of thick grime around the intake ports of the lower intake manifold. Obviously, I had a leak that allowed dirt to be sucked down the intake.

1. Does this sound like a bigger problem than just intake gaskets?
2. Should I take off the alluminum intake manifold to look for more leaks?
3. Could any problems with the IMRC cause this problem?
4. Has anyone else seen this before?

 

>1. Does this sound like a bigger problem than just intake gaskets?
Nope, sounds pretty normal.
>2. Should I take off the alluminum intake manifold to look for more leaks?
I wouldn't bother with it, you would have to drain the antifreeze, might as well just leave it as it is.
>3. Could any problems with the IMRC cause this problem?
No.
>4. Has anyone else seen this before?
Yeah on a 4.0 OHV Explorer motor. A lot of times the bolts vibrate loose when they get some miles on them.