Hey everyone I'm new to HP tuners I sold my DHP and got a IMO better platform. But anyways I had a custom tune on a PCM that a friend did for me. I noticed I was getting KR only during certain times ie going over a certain spot on the Verrazano bridge etc not when I'm on regular ground or anything. But I decided to put my PCM back to stock and I'm gonna go from there. My STFTs and LTFTs are not horrible but I think I may have a vacuum leak because LTFT is 16.4 constant at idle and 0 or close to it under acceleration and my mileage is basically 70% highway 30% street and still max 17-18mpg which for a pretty much stock car isn't great I feel cause people tend to get better mileage with the same model car. I'd like to know the best way to tune for this specifically what I should tune and how I should tune it? Thanks for the help my cars specs are...
1997 Pontiac Grand Prix GTP (Supercharged 3800)
Cold air intake
3" catted down pipe to straight pipes
10.3mm ZZP wires and AL 605 plugs