I am looking to get a piggyback system for my 05 srt-4. I am looking into them and they all cost so much. I can get a good deal on a new apexi safc-II but needed to know if anyone else uses them. I would really like to know how they work and if they show you the actual air/fuel ratio (ex.14.7) or if id still have to buy a seperate gauge. Just needed to get some imfo. before I buy. Thanks for the advise in advance.