My 01 cobra idles funny when you stop at a stop sign it goes up to about 1800rpm's for a few seconds and then back to normal. Is this normal or is something up? Maybe a vacum leak? I hear some kinda ssssszzz noise behind the passenger dash. I joked with my husband and said it was the cobra in there lol. Anyways can anyone give me their input. THX

 

if it keeps persisting up and down it could be the TPS....the szzing sound i have a similar sound but thats just the fan that doesnt stop unless you turn the car off....also possible gunk in the injectors wont hurt to grab a can of sea foam and throw it into a half full tank of gas

 

not likly unless it drops low for the injectors

 

i would bank on it being a vacum leak, i say go get it vacum tested.