Misfiring Issues - Typical Resolutions Not Working

Short backstory to why I'm here...

I have a 2007 Tundra 5.7, and I have long travel suspension with fiberglass fenders and bedsides. I originally ordered the glass bedsides online and didn't realize I had to opt for the fuel door cutout. So when I received them, no fuel door. So I decided to route the fuel fill up to the bed rail, and use a type of boat fill cap with and external vent. It has been like that for over a year, no issues, except for the CEL (leaking gas cap). So, I was away from home for work and my wife kept telling me that my brake lights (rear and third) kept coming on randomly and staying on. Like something pressing the brake pedal. Well, before I made my way home, I knew I had that issue to figure out, but also decided (a dumb idea that I end up regretting) to get a sealed fuel cap, instead of vented. In my mind I assumed that the vent must be causing the leak code, and that maybe the vent happened through the charcoal canister that pulled air from up front or something. So when I got home, I installed the sealed fuel cap, and a new brake light switch. Went on a test drive. Eventually, on my way home, I started getting rough running and misfiring. Barely made it home, popped the fuel cap, and it sucked in a lot of air. Realized my mistake, and reinstalled the vent. Started the truck back up, still misfiring. Codes were saying "random" and various cylinder numbers misfiring with my cheap little code reader. I also noticed at this time, right after I started it, that the gauge (tuner) in my dash corner, which has been there for years and always pulled the gauges up, said "new vehicle detected". Never has it done this before. So I decided to replace the fuel pump, coils, and spark plugs. Assuming I either stressed the pump, or fouled the plugs. I went back with OEM everything. Still misfiring. Had a neighbor come by with a fancy snapon computer, that consistently said and still says cylinder 7 misfire. So I swapped the injector from cylinder 1 to 7. Still misfiring out of 7. Did a compression check on the entire drive side bank, and everything was good. Changed out the fuel pressure regulator. Still misfiring. I checked for spark with a spare coil and plug on 7, and it's sparking. On top of that, the damn brake lights still continue to turn on all the time. So I'm at a loss right now of what is going on. But wanted to get some ideas from others....the "new vehicle detected" and the brake lights, along with the misfiring, could my ECM possibly be failing? I'm out of ideas

 

I have questions?? you swapped the injector?? or the coil? how old are the sparks? What type of sparks are they?? Have you checked the spark plug??

 

I swapped injectors for 1 and 7. Cylinder 7 still continues to misfire. Spark plugs and coils are brand new denso.

 

I would still swap 7 with a coil in bank 2. In case it may be defective... also check that battery ground wire, specifically the wire that goes to the fender

 

Replaced the ECM and everything is running smoothly again. Don't know how it got messed up but glad to have it running again.