Driving home tonight my XK (4.7L) shut off and the check engine light came on. Started up fine and drove home. When I got home I ran the code and got P0274, cylinder 5 fuel injector. It does seem like I have been getting worse millage then normal, but I have been doing a lot of in town driving and running the AC on high. It has almost 120k miles and has mainly been driven in town recently. I do put 87 in for gas, but run sea foam often. Does this sound right? If so I do not think I am mechanically inclined enough to do it myself, what should I expect to the repair cost to be? Looks like I'll be driving the XJ trail rig until I can get the problem resolved.