Hello, as the title says I have a 04 xj8, recently was driving and had the engine light flash on and it go into restricted performances mode, I was quite low on gas at the time, I got more then went and got the engine codes read. the whole time the engine was misfiring. the codes go as follow, p0202, fuel injector circuit malfunction cylinder a2, p1774, can timeout gearshift, p1798 can transmission control module instrument cluster circuit malfunction. The last code i have had for a while after some pest damage, but the other codes are new. I have already bought a new fuel injector and plan on replacing it following workshop manual. how difficult will this be, along with is this a realistic job for someone in their garage. Also any idea on the gearshift code? The car is at 119,000 miles if thats important

 

With all of those codes popping up, the first thing that I would do is to make certain that the battery terminals are clean and snug while checking the earth grounds as well. Regarding the injector (which would seldom fail), you can check its proper operation with a mechanic's stethoscope while the engine is running. If you hear the injector clicking, then it would be working.