Hey guys, unfortunately I'm about to share an essay with all of you...
So the past few months I have been getting some strange and random problems. I'm just gonna go down the list chronologically...
Ever since I bought the truck (summer 2-3 years ago) I would get a P0302 code (cyl 2 misfire) about once a month. Tried chasing it down for a while (replaced sparkplugs, wires, coilpacks) but couldn't ever get it to fully go away. It's had a bit of an idle sputter too (see video here), but never caused any real problems though so I have just been clearing it off with the scangauge when it comes up ever since.
Now, my low beams went out. Well, not exactly the lights themselves, but the circuit. Tried to turn them on one day, and got nothing on either side. Tested all the fuses, relays, circuits, wires, entire HID system, everything was good. Couldn't trace it back farther than the HDM relay in the front fuse box, which is apparently not receiving power at all. I assumed that since it was in that whole low beam control circuit that it was computer related (BCM) and I just needed a new controller, so for the time being I just took the wires in my HIDs and flipped 'em backwards so I can use the high beam circuit to turn on my low beam bulbs by flipping the stick on the wheel forward, and just deal with not have working high beams (fine with me since I got the 50" LED bar).
Next up would be the forever-running engine. Around 8-10 times within the last month or two, I literally could not get my engine to turn off. The first time, I parked, turned the key off, and for 5-10 seconds nothing happened. Everything was still on, including engine. I turned the key back on and then off again and it worked. Shrugged it off, went home. Second time, same thing happened except after I had turned the key off and it kept running for 10-15 seconds, all my dash lights started going haywire. I watched in horror for a couple seconds, then it shut itself off. This happened around 2 more times before I replaced the ignition switch. It worked fine for 2 days, then started the same thing again. The last time it happened, I had parked and turned the key off, engine kept running, and I just waited for it to turn off. Nothing happened. 5 minutes of key on/key off and nothing would work. The ONLY way I got it to shut off was pulling the fuel pump relay. 2 hours later, I got in to go home and trans starts acting weird. I feel like I don't have any power and I realize it's stuck in 2nd or 3rd. I try forcing it to downshift with the stick and it works once, and after that I'm stuck driving 20 miles home in 3rd. I decided this was another load of computer BS so I pulled both my batteries and waited an hour. Hooked the power back up, and no problems for a couple weeks.
Now, within the last month, I've had 4-5 cases of my engine just shutting off. Not dying out or stalling, just shutting off. No weird sounds or anything, just sounds like I turned the key off. It happened once right after (2 minutes or so) I parked in a parking lot, then a couple days later while stopped in gear behind an unloading school bus. Then again a few days later while I was out on the trails rolling down a big hill with the gearshift in D1 to make it easier on my brakes, I got to the bottom of the hill and noticed the engine wasn't running. Considering there are never any weird sounds and it just acts like a normal engine shutoff with no codes or anything, AND remember I just replaced my ignition switch, I just assumed it was another computer problem that I couldn't really do anything about at the time.
3 days ago I went driving around at the local offroad park. No problems, had a great time. The next day, I drive to school and it feels kinda rough.. Didn't have time to think about it so shrugged it off for the time being. 3 hours later I have to drive 10 miles to go to class on another campus. I get half a mile down the road and notice the engine light is on. I figured it was just that P0302 coming up for this month, but the scangauge says its P0304 for cyl 4... Huh, weird... Oh well, don't have time to deal with it. 5 miles farther and I get on the freeway, and the engine light starts FLASHING. I immediately shut off my AC and radio and slowed down so I could hear, and I was definitely running on less than all 6 cylinders... Class was only 2 miles away so I went ahead and drove there and just had my dad come pick me up on a trailer later. Again, I thought this was some computer crap, so I went to the the local U-Pull and got a PCM, BCM, and 2 brand new-looking coilpacks. Went home and swapped the 2 computers in, did the CASE relearn, and swapped out coilpacks on cyls 2 and 4 (only codes I've ever got were for cyls 2 and 4). I found cyl 4 full of water, with the sparkplug submerged. I blew out the water with an air compressor and made sure the rest were dry as well. Started it up and it runs smooth for a few minutes, so it was just the water in there, right? So I put my tuned PCM back in and tried it again. Runs smooth down the road for 5 miles or so, so it MUST have been the water. SIKE. Drove to school fine today, but completely lost a cylinder on the way home again, flashing engine light and all... until about 5 minutes later when everything starts working fine again the rest of the way. I unhooked the batteries for an hour, plugged them back up and started the engine, and missing a cylinder right from the start. Except this time, engine code is P0301 for cyl 1... WTH!?!?!?
As of now I have concluded that the computer has NO idea what is actually going on in the engine... And I have NO idea what to do next. I'm about to leave for a 2 week long trip and I don't have just a ton of time to figure this crap out. My current best idea is just to post this, and also show it to my dealer mechanic buddy and see what info I come up with. If anyone has come across these wacko problems before and has any insight, it would be MUCH appreciated.