Rep Power: 0

Okay here's the story guys I bought an EP2 manual (D16V1) the engine is the same as the D17.

​​​​​​When I bought the car the idle was fine but sometimes it would dip down to 600 and the car would shake.

I got a throttle body from a friend that was free with the IACV on it and all other sensors.

I replaced mine throttle body and found out the friends one was crapped out and returned my original one.

After that my idle would stick at 1500-2000 whenever the car was moving or I given it any throttle input (neutral downhill or creeping). So basically I give it any throttle input it would surge to 1500-2000 stat there and return to 900. If the car was just rolling in neutral it would also surge by itself to 1500-2000 and come back as soon as I stopped to 800-900.

I tried a third different throttle body and IACV that was confirmed working and it's the same exact issue.

I also sprayed all the vacuum lines with brake cleaner and couldn't locate any vacuum leaks.

The weird thing is after I returned my OG throttle body and it's senors I went on a trip that was 300 miles constant highway at a constant rpm and speed. When I arrived to my destination my car idled fine and there was no issues. On my way back i ran out of LPG (liquid petroleum gas) and was driving on gas I stopped to topped up, shut off my car and turned it back up again and a check engine appeared and the car was idling like **** again. The check engine is gone and was LPG related.
My car has this idle problem running on gas and LPG.

Any suggestions, ideas?
Do I need to do idle relearn maybe?