05 SS l67 starting to sputter under load. Where/how do I start diagnosing?

 

more details needed. How many miles on the car? Have you maintained it, ie. change plugs at 100k, or not, do you have 150k miles with old plugs? Any other codes? Do you have a OBDII code reader to get live data to check if your oxygen sensors and MAF are reading within tolerances? I don't know much about S/C maintance, i know the snouts need a rebuild after a bunch of miles on them.


Sputtering is likely from lack of fuel, or a clogged cat. But with a supercharger, if might be an air issue too as you need to have boost.

My guess would be lacking fuel. Check fuel pressure to make sure it's not low. Then check O2 sensors and MAF values with an OBDII reader if you have one. If throwing $ at parts and if fuel pressure is low or air is low; cheapest routes are to clean MAF sensor, replace fuel filter, replace fuel pressure regulator, replace MAF, clean fuel injectors, replace O2 sensor, replace cat.

Does it struggle when going uphill when you floor it on flat terrain?

 

Sorry should have been a little more specific. No codes. 160k or so always maintained. Recently done plugs, wires, coil packs. Seems to be a fuel issue. It only starts sputtering when I really give it power. No cat. Also, it started suddenly. Was running thru 3rd and right at the top of the rpm it started sputtering. Since then giving it 3/4 or more throttle seems to cause it.

Im gonna change out the injectors and fuel filter and if that dont fix it ill come back with more info. Readings and such.

Thank you.

Side note that I hope isnt related but...
A couple weeks ago I noticed a plug wire was melted on the headers and was causing it to run like crap. Must have been grounding. No blown fuses but is there anything I should check from that issue?

 

You can get injectors professionally cleaned, i used injectorrepair.com, $15 each. I used him for my Jeep YJ, they were low flowing 5-8% less than normal before the cleaning. Or for less $ you can just soak them in cleaner (see internet videos) or use some cleaner through the fuel system after you get a new fuel filter on. FYI- The injectors have a small filter on them, and the fuel pump also has a small filter on it.

I'd probably start with the fuel filter and see if that helps. Then I'd go to the injectors.

The plug issue, I would think it was grounding. Buy you might want to pull the spark plug it was going to and check that out to make sure it's gapped properly and not damaged.

 

Just a follow up, it WAS the plug wire.. The same wire I replaced a few weeks ago after the previous one was melted.