Why is My 2008 g8 is chugging/sputtering when I am driving down the highway going 60?

Bad fuel, fuel system problem, ignition problem, clogged injector, old spark plugs or lead wires, clogged catalytic converter...should I go on? Have the trouble codes scanned even if the "check engine" light has not come on and start from there. Could be many possibilities. Reply if you can provide any specific symptoms that may give us a clue where to start. It may be something simple. When was the last time the car had a basic tune-up and how many miles has it run?

P0507 code 60,000 miles 10,000 miles maybe on new tune up no wires though not fuel drove almost full tank b4 issue random sputtering inconsistently drivable cutout then will run fine cleaned throttle body and maf cleared codes popped back up 2 days later no catalytic converter

Throws same code hasn't sputtering or chugging for last 60 miles now

With no cats these cars chew up o2sensors especially the upstream . If it's the o2 it will continuously get worse. If you have exhaust your car should of been tuned at a shop and they can also turn your back o2s off(down stream) but the front 1s should go for at least 20k if everything is correct

I’m having same issues but with a p0420 code but I just bought the car and replaced timing chains not sure if the car had a tune on it when I bought it. After I changed the chains it started having a slight backfire out the exhaust and the p0420 code popped up I took the cats out for a day and it was still doing the same backfire. But sometimes when I drive on the freeway the engine light will flash but no misfire codes please help

Were in a 2008 on the interstate rn and it's a g8 automatic. But has that sport shift thingy..in 4th gear the car runs fine and smooth but 5th gear just studders like it's missing. It already jumped time once and we ended up with a different engine and shes just been funky every since