You dont need a scanner to pull codes either,so dont waste your money buying one.All you need is a short piece of wire to make a jumper out of and a test light (since you dont have a functional check engine light) The test light will flash the codes out,to replace the non existent check engine light.
1) The jumper wire gets inserted between the single terminal (STI) connector and the Signal Return terminal @ the diagnostic port.
2) The test light gets inserted between the (+) battery post and the STO terminal @ the diagnostic port.
I see a possible issue already (depending) The car is running a maf sensor,but you stated it has a map sensor too.MAF uses a BP sensor,not a MAP sensor.The same sensor can be used,but you need to remove the vacuum hose from the map sensor,leave its port open to atmosphere and plug the vacuum hose.
Is that airbox completely sealed,except for the opening on the rear where it receives its air supply from??
I only see a couple small vacuum hoses,so Im not sure how youve got things supplied?? You should have a vacuum hose running from the upper intake to the evr solenoid then another hose from the solenoid to the egr valve?? The solenoid regulates/supplies vacuum to the egr valve,so make sure those hose routings are correct.
To rule out the egr valve,as a possible cause of the rough idle,remove the vacuum hose from the valve and plug the hose.Take the car for a test drive.If the idle issue clears up,trouble shoot the egr valve & evr solenoid.