Quote Originally Posted by Fivefingerdeathpunch View Post
You have to tune for whatever fuel you choose to use but the stock computer can do both fuels if you know what you are doing.

It how ever can not do both fuels at the same time, it's either one or the other.
I have an 04 Pontiac Grand Prix Supercharged and now that I've just started modding, I just found out that my Car was made for 91 Octane and I've been putting 87 in it all this time. Had me thinking for a minute that I may have been damaging my car. PCM tuned for 91 and I'm putting 87 in the tank

Sent from my SM-N950U using Tapatalk