Ian Shaw

Can anyone help me? I have a 99 4.0 auto. The other day p0306 came on and it was misfiring. I was able to get it to stop for 2 days by changing the spark plug out. Well that happened Saturday morning. Well Saturday night my serpentine belt shredded and half got stuck in the clutch fan while the other half stayed on and continued to turn the appliances. Well I didn't know this had happened until I looked down and the temp gauge was up to 250. Well I shut it off and checked under the hood and did then I changed the belt and went on without any further problems. I did not have a problem yesterday but today I was going down a road that had about 5" of water on the driver side and water splashed all over the driver side and as soon as I went through the water it started missing again. This isn't a bad misfire, I can still drive it around but you can tell it's there. Well I figured water may have gotten around my air filter and it was dirty anyway so I went ahead and no changed it and still nothing. Same thing and jus before so I go home and start unplugging sensors one by one and the only one that didn't effect the engine when I unplugged it was the one to the left of the throttle body (when looking at it from the front). Well after that I went through and did the injectors the same way. Every injector made the engine misfire more than before except with #6. No change when I unplugged it. That's where the first two codes come in play at in the picture below so I'm not worried about them. At this point I decided to drive around some with everything hookee up like its supposed to be and then pulled over about find unplugged #6 and drove back home and there was little to no difference before and after. but the other codes except for p0306 came into play somewhere along the way after all of that. Can anyone help me with this? I think it may be the injector sticking open or something but it cranks on the first try still. So I'm kinda stumped