I've installed 2 K&N CAI when I started to go that route and I got a CEL both times.
Than I decided to go to the open air filter route like I see on many many Stangs that don't have a heat shield.
I installed a G5CR CAI over 2 years ago and man I felt the difference. I runned my car with a ACS Nickey Chicago Hood with a ram air to the filter for 2 yeas and I recently changed it to an ACS TL1 Hood with lots of hot air coming out and fresh air coming in . I never regretted going with the open filter and I'm not a fan of closed in-a-box CAI which I beleive are not getting enough fresh air drom the grill.
I'm getting the car dynoed in the next weeks than I'll get the exact figures on HP and Tork gains
