What makes an idle rough? Bad O2's , TPS? IAC ? Could leaking do-nut gaskets at the y-pipe do it ?

I've got a bit of a rought idle and I'm trying to pin-point stuff it might be

 

Hows it idling rough? is it jumping between rpms?is it idling high or low?TPS and IAC can cause idling problems.I know i had them

 

i had it on a scanner it at idle the rpms went from 815-845 back n forth, and it just feels a little rough, hard to explain, it isnt right at idle but WOT if feels raped...

 

Try cleaning your IAC with some cleaner and a toothbrush VERY carefully. Also if you haven't done so clean the TB plates and and the area behind them. After put the TB back on and make sure all vacuum hoses are connected. I had the same type of problem. My car idled at like 850-900 and it was putting a strain on my brakes and my leg ).After cleaning the TB and the IAC im now idling at 700-800 and idling beautifully.So try it out and let me know how it works out.

 

Would I be better off just replacing that?

 

I'd try cleaning it first.Carbon buildup can really disrupt its function.Also a new IAC I think is around 80 bucks.The throttle body probably needs to be cleaned anyway by the sounds of things.

 

What do you recommend using to clean the IAC and throttle body? Carb cleaner?

 

I used carb cleaner. Worked well for me.

 

SEAFOAM! havent ever used anything better