Do you have a video of the gauge when the idle is fluctuating and/or the hissing noise? When does the idle fluctuate? Always?

I think a lot of RSX owners have this issue (including me) and I also haven't found a concrete answer yet (beyond the obvious clean throttle body, replace iacv, etc), and I'm curious how similar your issues are to mine.

There are a lot of posts regarding this. Maybe you could go thru those and try those solutions and tell me/us what fixed it for you? 😂

 

i was running into idle issues with my ep3. the quick fix i've been using is to disconnect the vacuum hose going from your air box to your valve cover (ie the idle air assist valve). the iaav is only suppose to stay open for certain temperature duration. ie. it's suppose to help the car with cold starts, but when the car reaches temp it's suppose to shut. so a quick test is turn your car on let it get to operating temperatures and see if your iaav is still pulling a vacuum (ie sucking force) if so, then yours is faulty and stuck in the open position.

so plug the vacuum hose with a bolt and a zip tie of some sort and the engine should not be pulling extra from the iaav. after doing that my car has been idling great. i did take apart my throttle body while replacing my clutch and cleaned the iacv thoroughly and make sure it spun freely, but i still had idle issues thus i ran into the fix above. hope this helps.

 

All you need to do is the procedure for k series idle relearn may take you a couple of times to get it right but should fix you up YouTube it 😉 you can do it

 

ngl i replaced my iacv, cleaned my throttle body, and did the idle relean and i still have the issue (altho it did get much much better). now my idle doesnt surge, but itll hang a bit high sometimes. I think it may be the throttle cable catching or snagging on something. Might have to take a look

 

Curious.. the IAVC TQ spec calls for 2lbs, it is easy to overtighten that gasket