2003 3RZ feeling like a moped, slow and struggling under load.

[Pota]

My 1895 toyota hilux has got an updated engine being a 3rz out of 2003 2wd hilux. The swap was done about 5 years ago by one of the previous owners.

Over the past couple months there has been a power loss on the low end of rpm when accelerating, the car often chugs along very rough under load.

Its been getting worse, Ive replaced the fuel filter and fuel pressure regulator thinking that was the cause but nothings changed, cleaned the MAF changed air filter still nothing changed.

I'm trying to figure out how to read code from it if thats even possible but i couldn't find any obd 2 port under the dash or near the drivers footwell. I've tried to read the code by connecting two terminals in the diagnosistics port in the engine bay but the check engine light didnt flash at all.

If anyone got any ideas about what the problem could be or how to read the code that would be much appreciated.

Thanks Sam.