Lets get right to the point.. So i have a 96 pathfinder with 200k on her. I have always had a very slight miss that you could hear from the exhaust idle. But now after the car starts up it runs fine no stalling or hesitation but after it warms up the car will start misfiring worse and worse, like when i let it sit after driving and get back in it. I have changed the spark plugs and wires. Did the cap and rotor. Did not make any difference. The car throws no CEL Im starting to think it might be the ecu.. because i unplugged the MAF and the car died, started it back up and it ran with no CEL. But when i plug in the scanner the MAF code will come up.. after driving for a long time especially in hot days the car is almost undriveable unless kept under 2k rpm.

Here is two video clips i made to show what im talking about.

https://www.youtube.com/watch?v=PMR1AjQhh6U
https://www.youtube.com/watch?v=04P-ylg1unQ

Any help would be greatly appreciation

(I have an extra ECU and also bought a fuel filter)

If you checked the codes after you unplugged the MAF, it would make sense that you have a MAF code unless you erased it afterwards. If the fuel filter has been on a long time, it would make sense to replace it first before going any further. It could be that the fuel pump is starting to fail. If you can duplicate the issue after it warms up, I would get a fuel pressure test gauge to check what the fuel pressure is. With the engine not running, it should be 40 psi or more. Running, it should be around 34-36 psi. If the pressure is too low and the fuel filter has been replaced, replace the fuel pump. You can access it under the left, second row seat, IIRC.

i'm changing the ECU right now. Fuel filter is next. The only reason i unplugged the maf is to test if the cars CEL would come on. Other then that no codes again.