Need Help! Bad Idling

Hello Guys,

It has been some time since I been on here. However, I encountered some serious issues with my car since I let my friend borrow my car: 2000 GP SE 3.1L 134,000+ KM.

The issues or damages:

1. Catalytic Converter damage by the hedges (possibly due to hitting a curve)
2. Heat shield severe damage (possibly due to hitting a curve)
3. Oil Pressure sensor stuck out causing excessive amount of oil to leak out.
4. Rear exhaust pipe hanging off the hangers (possibly due to hitting a curve)
5. Engine idle rough
6. PVC Valve & elbow (NEED REPLACEMENT)

The things I fixed thus far:

1. Replace spark wires
2. Replace all spark plugs
3. Replace Oil Pressure Sensor
4. Attached Catalytic Converter back with donuts & rear exhaust pipe
5. Cleaned MAF sensor
6. Cleaned IAC sensor at 131,000+km & Throttle body
7. Replace EGR valve with junk yard find ---> Bad idea
8. CHANGE OIL --> AFTER FINDING LESS THAN 1QT in the ENGINE (Due to Oil Pressure Sensor leak)

Currently, the car is still idling rough and I can't figure it out. I assumed the EGR valve or CAT converter might need replace but the stock U-Bend CAT converter appears to be okay despite the damage heat shield and anchors.