97 4 Runner 3.4

I have a 97 4 Runner 3.4. I bought it off a guy and now it won’t stay running. I crank it up and to keep it running I have to pedal the gas and it runs rough when I petal the gas. When I let out of the gas it does. I have replaced MAF, cam sensor, crank sensor, timing belt, IAC sensor , plug and plug wires, TPS. Also I can’t read CEL because the obd2 port doesn’t work I have replaced the cig fuse as well for the obd port and still nothing and help would be appreciated thanks in advance.

 

Well obd port is bad news for sure

Have you changed the fuel filter?
I'd get the obd fixed as top priority

 

I was going to say fuel pump. About the only thing left. You can check the fuel pressure regulater by hooking up a vacuum gauge. Its easy takes two minutes.