Traffic m9r looses all power at 4000 rpm

partially plugged catalytic converter !

One guy I know traced it to his in-tank fuel pump. The computer reads that all of the electronic components of the pump are running at optimal, but a pressure gauge connected to the fuel rail on the intake showed the pressure was 58 psi at an idle and it dropped to 45@ 2000 rpm's. 58 psi is minimal for a big block, 60 is optimal. The book shows the small block should be around 50 to 55 psi for optimal pressure. The drop in fuel pressure causes the engine to lean out under a load such as accelerating and pulling and could cause the engine to burn a piston from the increased cylinder temp. I am not certain how this would cause ignition power loss though, unless that fuel pump has a safety cut out for electrical shorts, real or perceived by the computer.... Have to talk to some friends about that.

vacuum lines, to map sensor/ cracked air intake tube check all electrical connections/loose air intake clamps

I would check the EEC relay, and the fuel pump relay too. But it sounds like the ignition module is loosing power, or the pump is not getting power after the engine starts.
The computer must see oil pressure or RPM to power the pump relay after the engine starts.

I'm not sure of engine liter size? How long since a tune-up? I always check for codes, even if lite isn't on. Some of the national brand auto stores will check codes for free, if there are any, just tell them your lite has been going on and off.
Use a gage and check proper fuel pressure. I can give you fuel pressure spec because I don't know liter size of engine? Some vehicles don't have Schrader valve on fuel rail, which makes checking fuel pressure a little awkward.
If you have electronic returnless fuel system, you have a fuel pressure sensor, hopefully on the fuel rail. The yellow wire should be for fuel pressure, engine idling, use digital multimeter on yellow wire. 3 volts = 43.75 psi. 2 volts about 20 psi less. 4 volts about 20 psi more, so you get the picture.
The basics for a rough idle, check for a leak of some kind, fuel--egr--vacuum leak.

OIL PRESSURE SHOULD BE 70 PSI@4000 RPM 30 PSI AT IDLING. MAKE SURE OIL FILTER AND OIL BEEN CHANGED AND MAKE SURE OIL LEVEL NOT LOW.AND YOU USE THE RIGHT OIL.IF ALL IS GOOD OIL SENDING UNIT COULD BE BAD.

check the air flow meter operation and rangeing

check your vaucumn hoses for leaks any leak in that system will effect your fuel pressure regulator and fuel rail that controls the running ability

If you disconnected the Mass air flow sensor the car should have die out at idle. Check fuel pump pressure at the fuel rail should be 30 psi at idle. Low fuel pressure will cause your po 171, 172, problems which could cause the other to problems. You might be needing a fuel pump and filter.

At operating temp 171 - 181 F, with SAE 10w-30: idle @ 700 rpm 11 psi min, 1200 rpm 28 psi, 2000 rpm 43 psi, and 4000 rpm 57 psi.