I dont know why
I was useing 87 gas b4 and i am useing 91 right now
today I am driving on highway and try to put more gas.........damn wut do i want to say
ok...when I am useing 87 gas, the max boost was in the middle between 0 and +40(stock boost gauge)
but after I use 91(today), the boost was easy to up to +40 then ECU cut the feul and the engine was shaking.
sorry for my pool english but I want to know was that problem or no?
if yes what should I do? actualy I am not sure it was the gas's problem but never in b4.
plz help.

 

it may become a problem. i dont think it should be in the gas tho. maybe check out your wastegate make sure its still working right.. thats only thing i can think of for making you overboost. 8 psi is cutout on a tII stock psi is 5.5 so im not to sure.. im most likely gonna be wrong but o well it just a thought

 

I'll check it out tomorrow
thx a lot man