When extremely foggy outside or after running it through a car wash check engine light comes on and is misfiring. It was very foggy and misty and could not get it to start and had it towed to mechanic. First they said the fuel pump was very low pressure and it was replaced as well as fuel filter. When I went to drive it home I didn't even make off off the parking lot. It acted like it was going to die.

So then they replaced OE replacement wires (coil on plug boots), all 6 Morotcraft spark plugs and plenum gasket. Work done on 1/29/13. Have 54,000 miles on it had original plugs and fuel filter. I know, not good. But I do have the oil changed regularly.

After I got it back it seemed to still run a little rough and slight hesitation on freeway acceleration. Seems to "catch" and then accelerates normally. But that's not the main issue.

Ran it through the car wash a few days later and kept engine running and no problems. Ran it through this afternoon and again kept engine running. This time something got wet and it it sputtered a lot. Acted like it would die at stop lights. Went a few blocks and parked it. Was gone about 10 minutes. When I started it up the check engine light came on and it was obviously misfiring and drove it straight home.

The job notes are:
Running extremely rough after fuel pump replacement
Cylinder/plugwell #5 had oil in it;rear
plugwells had condensation

Original owner, 2003 Ford Escape XLT, 3.0, 54k miles.

Please help. I have already spent a small fortune on these repairs and rental car. Will have it towed back to shop and have them diagnose whatever code it is on their equipment. I am a female and I don't feel comfortable doing much work on it aside from changing the air filter and don't have the tools regardless. I just don't want to be taken advantage of and the expense of replacing Part A, doesn't work so replace with Part B, etc.

After googling, it seems they probably should have replaced the valve cover gasket? Any ideas? What can get wet to cause this? Or moisture from heavy fog?

Edit: Temperature on the mid-40s and let it sit for several hours in the driveway. Just started it and check engine light still on and misfiring