Do the car was running strong and fast. Then out of nowhere after I filled up the tank, the car sometimes sputters. It doesn't do it often. But when it does it acts like a fuel issue. Im going to check the fuel press. Its got a new fuel filter, plugs and wires, new coil, new icm, just changed the header gaskets to percys, new arp bolts. Had the exhaust gone over and checked for bad welds and leaks. Maf checks out. Tps is gods. Im also thinking of changing the o2's. Probably couldn't hurt. I run injection cleaner every 3 tanks, and only run 93 octane fuel. And only from reputable gas chains unless I have no other options. Any other suggestions or ideas? The thing sputters like its falling on its face, then it straightens out. Usually after I barely lift off the throttle. All help is appreciated. Thanx in advance

 

dying pump? Check pressure under a heavy load and see if it is falling off.

 

Are you still running the same tank of fuel?

 

No sir, I've filled up twice since this started happening. Also the fuel mileage has gone down, and the engine sounds different to me. Still throaty, still solid. Maybe its my imagination, but its also sounds lime its workin a little harder runnin down the interstate. That really sounds stupid considering the fact that it runs 80 when im barely touching the pedal. It sounds like its under a bit more load. And I had the compression tested, according to jk chevy my engine is very very healthy. Testin fuel pressure tomorrow. Also, I know people say fuel injection cleaner and octane boost don't help, but I run octane boost, injecter cleaner and heat through my fuel system regularly. I use one at a time, and every third or fourth tank. Hope that makes sense lol