2002 E150 econoline, 4.7 V8, 98K. Engine has begun to mis-fire (again), normally within a few miles of it really being bad (under load, up hill) it will set an engine code, and I will change the COP (6 so far in 8 years). This time it just wont set any code, it mis-firing very badly (under load). Short of using the spare COP and just replacing every unit until I find the bad one, is any other way to find the cylinder? I do have a decent OBD unit that will show me live data, not sure where to look. any ideas?