Thread: Need help....sputtering bad

Check coils? Try swap one to the other and see if the misfire changes cylinders.

Per the "Safely Modding your 3800 powered car" thread...

you want to keep a hot spark. NGKTR55/AL104's for your 3.4" Setup, TR6's are a tad cooler

AC Delco Factory Replacements: Stock
Autolite 606: Stock
Autolite 605: 1 Heat Range Cooler
NGK TR55: 1 Heat Range Cooler
Autolite 104: 2 Heat Ranges Cooler
NGK TR6: 2 Heat Ranges Cooler
Autolite 103: 3 Heat Rangles Cooler

6) Exhaust - Here is where a lot of misconception tends to occur. Many people think that when someone says exhaust work that they can run 3” straight pipe from the cat back and drop to a 3.4” pulley and think that they have done enough exhaust work. Hardly. The cat back is the least of your worries as is flows good enough and has been dyno tested to not show signs of flow issues until 350+WHP, which is around 400hp at the crank.

Other than your Borla catback and "modded dp", what have you done to actually increase the flow (ie- are you running stock exhaust manifolds?). Hopefully this is just a bad coil or injector. Is it misfiring on this cylinder only, or multiple ones?