2000 2.7 L has only PO172 code and runs rich

My 2.7 L Tacoma runs rich it’s got gas coming from exhaust. The only code is P0172 decompression check did fuel pressure checked all good replace numerous parts, including fuel, pressure regulator, cleaned EGR valve. I see what might be a pinched fuel return line. Any suggestions new O2 sensors new map sensor numerous new parts, new evap purge valve lots of dark spots around exhaust manifold could be from fuel don’t hear or see a leak. Any suggestions could be the pinch fuel return line? P0172 is the only code, other codes have poped. Generally, if another system is popping the code, it would give me other codes to lead me, but this is the only code, and it is indeed, running rich plugs are all black. Exhaust Black Toung badly caked up.

 

It has been doing this for quite a while, but it’s gotten worse over time amd Im throwing Parts at it that never seem to solve the issue, fuel mileage is horrible, amd just started a misfire on cly4 yesterday plugs are horrible solid black, It’s definitely running rich, but P0172 is the only code, what coild it I be missing. Could it be a slightly pinch fuel return line I’m sure I could be, but any suggestions? Could it be that my map sensor is not OEM? Could it be that some of the parts are not OEM? Could it possibly be the fuel filter which I replace but it’s not OEM maybe too much fuel going through filter? maybe the ECM? The valve cover gasket leaking a little bit but not real bad I’m going to fix that ASAP. replace both O2 sensors for Denzo. I Replace fuel pressure regulator with Denzo. Got a new MaF sensor checked intake air for clogs and got new air filter. Any suggestions? it’s been doing this for quite a while, but gradually gotten worse and worse to the point where now it’s misfiring on cylinder 4.