I have a 2001 Suburban 5.3, with 325,000 miles on it. It has an intermittent issue that starts with a rough idle, then stutters at take off. It doesn't do it all the time, just enough to be bothersome. I replaced the plugs (Delco platinum) & wires a couple of months before this started. (The hood sticker said gap @ .060, but the plugs said that had been changed to .040) I gapped them @ .050, and it ran great. After this issue started, I thought I got some bad gas, so I ran a can of Seafoam through it. Still had the issue, so I cleaned the throttle body. Nothing changed, so I replaced all the injectors & the fuel pressure regulator. It was much better after the injectors, but is still doing it. During all this, it has never had a check engine light come on, except when I forgot to plug the MAF sensor back in, so I know the CEL works. I have checked the vacuum & it sits steady @ 18 at idle. Most of the forums I have read & videos I have watched show different check engine codes, so I am stumped. Any ideas??

 

At your high mileage everything is worn for sure. Could be a MAF or MAP sensor running on edge of tripping a code but not bad enough yet.
I had a bad MAP that did not set a code but it killed 3 mpg and EVAP self test would not run for inspection for example in my '11 5.3
A great scan tool is needed for checking on what the system is seeing from sensors.
Change that fuel filter, they do not set codes when plugged, and can even show good fuel pressure at idle but not flow when you hit the gas. Those filters are 30k mile maintenance items.

 

Thanks for the reply. I'm not sure if my Suburban has a MAP sensor, but I'll check. Also, I forgot to mention I replaced the fuel filter recently