couple questions after aspire b3 swap

[joeboomer999]

Ok just did this swap and noticed two things happening.
1st- while sitting at idle from time to time the idle will drop quite a bit and stay there for 3-5 sec. Then return to normal, and when I give it gas for a second it seems to hang up at the new rpm and comes back to idle slower then usual. The one thingI ddidn't do yet was hook up the sensor in the exgaust manifold as I need a new one. Would not having this sensor connected be causing said issues? If not any ideas?

2nd- when I turn off the engine there is a hiss that lasts for around 10-15 seconds in the fuel cannister (ish) area (havnt been able to fully pin point it yet)... any ideas what could be doing this?

[bhearts]

I think the hiss is just vacuum bleeding off, mine last maybe two seconds but I don't have that canister. If you open the throttle then close it, and your rpm stays high for a while, it's only possible because of a vacuum leak, right? So maybe the little flying saucer shaped thing attached t to your throttle body needs adjust, manual trans only, or your throttle cable could be sticking, or maybe something with your idle air control system. Did you put festiva manifold on the aspire block?

[joeboomer999]

So hiss is ok?...it is manual tans. throttle cable isn't sticking and yes festiva manifold on aspire block

[joeboomer999]

Ok so the only thing remaining is the hiss... can anyone confirm hearing a hiss from around the canister area when you turn off the engine is fine?