what would cause a 98 integra type-r to idle ok but when i go to engage a gear the motor only revs to 2000rpms and bounce down?

its almost like having a 2 step in it but no lol. the car will only engage a gear if i really put my foot down. and if i try to drive it normal i bounce around like a rag doll in the car.

the car throws a check engine light and i pulled the code. the code is P0505 and is for idle control malfunction so i cleaned the iacv with carb cleaner and put it back on and cleared the code and im having the same problem again.

is there anything other than the iacv that could be causing this?

 

other than checking the wiring for a bad connection, short, or something i think i would just replace the iacv and go from there. good luck

 

If only I could get idle not to Buck down intermittently it wouldn't throw me the code and I'll be fine thank you I set the idle to 1000 rpms at the throttle plate adjustment everything is good at idle no bucking no code but when I put a load on the engine AC or put it in drive it all happens all over again

 

limp mode, the ecu sets a rev limiter to prevent damage from det or lean conditions. You just might need to replace the iacv sensor itself.