Truck has emphezima

I have a 97 Toyota 4Runner (4 cylinder, 2.7 liter, 5 speed) that I bought just over 5 years ago. Ever since I bought it it has had a coughing problem that does not seem to be RPM or speed realted. We do regular tune ups and oil changes. In the last year alone we ahve replaced the engine, cat, then removed the cat altogether, changed the coil packs twice, changed all pumps except for the fuel pump, changed the O2 censors, cleaned the mass air flow censors, cleaned the intake… even used Sea Foam. It doean’t throw any code either, and every mechanic I meet has no anwers for me either. I am just about at the end of my rope, can somebody please help me???

I don’t think that anyone here will really be able to get a handle on what a “coughing problem” is. When you provide a better description of the problem, also please clarify that you did in fact replace the entire engine.