my car spikes around 15 psi and than drops to around 11 or 12 psi. Is that normal?

 

usually. depends on what mods you have done. my car stock would spike around 15 then drop to 12 or 13. AGP makes an adjustable wastegate that will hold more boost than the stock one, or you could get stage 2 from mopar. or just ask if anybody has a stage 2 wastegate for sale, i do.

 

how much?

 

you can buy one new on e-bay for about $115