Evaldespino

I have a 2014 camaro SS which is now twin turbod with Hellions kit. After the kit was put on we began to tune it. It was having an issues where no matter how much timing we added or boost passed a certain point it would gain any more power. After calling Hellion they said it was the stock cats on it and that no more than 5 ibs of boost can go through them. So now im going to have them cut off as they are not necessary in SC. However the tuner I went through may be unavailable to finish tuning my car after. My car is automatic and is having some trouble downshifting now and when in reverse it has an odd sound to it. Anyone have any suggestions for a tuner in or near Charleston, SC? My tuner uses efi live and he did not lock it. Also suggestions for the down shifting and reverse? I was thinking it was the tune.