not much. between 2 and 5 if you are very lucky. ohh and sticking a huge opening at your tailpipe isn't gonna give you anything either.
what year
By installing an cold air intake on a mustang
30ish, depending on octane levels and type of plugs.
No.
Maybe 10 on its own. With other mods like a bigger throttle body and exhaust it will help out more.
From 5 to 10 horsepower.
cold air intake
10 horsepower.
about 2 wheel horsepower
You can start with Cold Air Intake, Then exhaust, then headers and ECU upgrade
The cold air intake may add 5-10 hp to the 335 it was built with.
Sound like a electronic problem. you should of posted the year and model mustang