I have a 2001 escape with 129,000 miles on it. Back early summer it started driving rough intermittently, it was hesitating and while driving and at times felt like I was driving over the rumble strips on the side of the road. As I bought the vehicle a year ago and it showed no past history of having the tranny serviced my mechanic said I should have him drain and replace 2 qts and add lube guard. He did this and it ran good for 2 weeks the hesitating again and showed a code of cylinder #1 misfiring. Then he replaced spark plugs, fuel filter. It ran great for 2 weeks, then same code again, this time replaced all 6 wire caps, ran great for 2 weeks, now started hesitating intermittently again and today emissions light came on again and was running rough again. Don't know if it has anything to do with this but my rear differential has a leak near the pumpkin, not leaking very bad at all but it is there. Any help would be appreciated.