When ever i start my car when its cold the rpms spike to 2000 to 2500 and stay there until i put it in to gear (auto) and then it goes does to the normal 300-400 and after it warms up and i put it into park the rpm stay down so just when he engines cold does it really spike. It wouldnt really be a problem if my car wasnt so damn loud but... it is. The only mods i have are all bolt ons i/h/e and i reset my ecu after each instal but thinking about it now the temp has changed drastically since i live in minnesota. Ill reset it and get back to you guys but please try to come up with all the other things it could be. Thanks

 

What temperatures are you talking about??? If it is really cold I guess it is normal. Your enigne is trying to warm up.

How long it takes it to drop down to 600-750rpm?
How long ago have you reset your ecu?
Exhaust leak?
Vaccuem leak?

 

Yea its normal. Your o2 sensor is in open loop, meaning its not reading your a/f maps. Its just putting a set amount of fuel in until your o2 sensor gets hot enough to read your a/f ratio correctly. On autos you can hear it more than standard.

 

^thanks guys so is there anything i can do to counter act it because like i said before its pretty loud and my gf's little bro wakes up when i leave her house at 3 in the morning which doesnt go over to well

 

Neutral, roll it down few blocks and start it up

 

Put a magnaflow resonator inline with your exhaust. Makes a deeper sound and quiets it down. Its worth the money. I speak from experience with it on mine.

 

^ i ahve one thanks though

 

Could try plugging the car in, not sure if that would help though.

 

My custom grounding kit that I installed myself helped smoothen out my starting idle when I had your setup.

 

Put cotton in his ears. You want your car at normal operating temp.

 

that is the funniest damn thing i've heard all day hahaha. i'm down for the cotton idea. the kid can always fall back asleep if he's that tired. that's what i do when my brother starts up his Impreza 2.5 RS and i'm sleeping. that damn thing is loud...maybe i need some cotton too.