I start the engine and it goes from 1500 rpms to 900 idle after 2 minutes. then it goes to 1100 then down to 900 after i start it a second time. Also I just put on an AEM v2 short ram intake on my car, and it feels the same, but for some reason i feel that i am wasting much more gas like the car is running too rich or something, more now, and it still was like this prior to this installation: rich. what could be wrong, and what do i do to fix this issue. I have a welded straight pipe instead of the muffler that kinda makes a backfiring sound after i let off the gas, should i replace it? Whats the best way to control air/fuel mixtures on my car if possible.

thanks.

 

An intake doesn't really do anything, you probably did something wrong when you installed it. I would go back and double check all your work....

 

Backfire is caused when gasoline in the cylinder isnt ignited properly.