I posted this on another forum but haven't gotten any answers so i'm gonna try it here. desperate.

My car has been bogging for a while now. And I've tried several things to fix it.
Welll.. A few weeks ago the idle air control valve went out and threw a code that the iacv motor was bad. So I bought a used one and put it on. I drove the car to and from work that night and it drove amazing. No bogging or anything. All my power was back and everything. But I got in my car in the morning and the iacv problem was back and it threw another code.

Check engine light is P0505 - Idle Control System Malfunction
cleared it and let it idle for 10 minutes Then at idle, I unplugged the sensor on the iacv and the rpms dropped but didn't stall. Did a compression test and it was 180 and 185 on all cylinders.

Also seem to be misfiring or breaking up at 4500 rpms but no cel? the whole rpm band is not smooth. it gets alot worse at 4-4500rpms I don't know if this is connected, but thought I'd let you know.

The wires look fine. Two right? Green and yellow I think. I unplugged it again to make sure I got the same result and this time when the rpms dropped, it made a clicking noise in the engine?

took it to a shop and they said to replace the iacv o-ring and the throttle body gasket. so i replaced both yesterday and then erased the code and let it idle for 10 minutes. car was still running bad. but the idle wasnt messing up. then today the bog was so bad that it was basically AT the white line before 0 before it caught and went. then i was parked and it was idling and it threw the code again. now i cant even let it idle for more than 30 seconds before the idle starts jumping and makes it undriveable again. so i have to restart it.

there's a soft whistle at idle and while driving. so i guess i have a vaccum leak somewhere. but i've looked, i've had a shop guy look, a master mechanic ase certified blah blah guy look. nothing.

also, the shop told me to clean the tb. so i took it off and cleaned it THOROUGHLY. and now it sticks 10x worse. (the butterfly sticks) happy told me to clean the spring next to the tb so i'll do that today.

i dont know what to do.
i bought ANOTHER iacv. 150 dollars. just so it can go out again the next day.
replace tb? replace intake manifold? replace engine? im lost.

 

bump

 

new iacv went out the next morning. help!

 

i'm basically having the same problems as you are. only difference is that i've cleaned my iacv and the problem persists. even had the distributor cap, wires, and plugs changed. same problem. i get code p0505 and p0108. i'm totally lost. it's such a pain to drive because my car will die 7/10 times at a stop. NOT SAFE at all. bump for answers. oh, and i drive a 99 SI

 

Good news! I took it to the shop today and it's my throttle body causing every single problem. Getting a new one and the car should be all better. Check into it! I have a 99 Si too. Good luck

 

dude im having the exact same kind of issue, That was going to be the next thing i looked into. thanks for keeping us posted.

 

glad i could help, i know how frustrating this is.