Hi, I have a 2013 Chevy Silverado 2500 6.0l with roughly 330000 km or 208000 miles on it and it just doesn't seem to be performing as well as it should, almost sort of gutless. I've changed plugs and have no codes showing. I change air filter at every oil change so not starving for air. I'm wondering if catalytic converters may be plugged and are restricting flow? I don't gave a ton of mechanical knowledge so just looking for some ideas.
Thanks,
James

 

Clean out your MAF, It probably needs it anyhow. It can often get dirty or go bad with no codes. Unless you are in lots of dust, you don't need to change the air filter every oil change, just blow it out with some air if you want to. How often are you changing motor oil? Have you changed the fuel filter at all? Could be lots of reasons why your ride isn't performing up to par. You need to get a scan-tool on it and see if you are running any OBD II codes, IMO.