This has been going on for sometime now so bare with me lots of details. So I bought my dodge nitro last Feb with 88,000 miles on it from the dealership. Ran fine for awhile then in June we took it to vegas. Got there perfect no issues at all but the 3rd day in on the way to the speedway the check engine light came on and the car started shaking like crazy and Stuttering was hard to make it go over 35 mph. So we hit the autozone they plugged it in told me failed fuel injector. Could not do it in vegas with not having tools or a garage but I bought the part anyways just in case we broke down somewhere and couldn't get a hold of the part and also bought fuel injector cleaner and threw that in right away. We were in vegas 2 more days and kept throwing cleaner at it headed back to colorado stuttering stoped but still didnt want to go over 55 mph maybe little rough idle when we would come to stops. Get home problem is over all together no check engine light and running fine figured the injector was clogged and all the fuel injector cleaner broke it up. So I did forget about the problem and never changed that injector. Fast forward to December 1st (111,000 miles currently). Problem starts up again check engine light comes back on, idling very odd at stops/slight shakes when stopped, feels sluggish like it has a engine brake pulling it down almost. So it's throwing up the same code again for misfire on 2. So we change all spark plugs, check coil packs, and changed the bad injector. Still same code drove about 2 days light went off. Then it would just go back and forth with the light being on for day or 2 then off and back again with the issue persisting aswell. Then it gave me a random code only once for faulty o2 sensor and or catalytic and back again to the standard codes it's been giving me haven't seen that random one again. Has anyone ever had issues like this before? I just don't understand anymore and I'm not a car type person so I only really know how to do the simple stuff.