Date registered: Mar 2005
Vehicle: '01-E320 & 02-ST2
Location: John 15:18-19
Mentioned: 0 Post(s)
Quoted: 35 Post(s)
You might try posting in your car's native forum, but here's a couple of thoughts.
Five month old gas isn't necessarily bad, but it's certainly getting there. The first thing I'd do is go on a nice long drive and get it down near empty, then only put in a few gallons. If you're only going to drive it rarely, leave it near empty, then put in fresh gas when you take it out. It's also possible you have accumulated moisture in your fuel tank so a can of dri-gas or a premium treatment that includes a gas drier may help as well.
I'm not sure if the V-8's CPS is as occasionally buggy as are those in the 6s, but that may be something to check if it's not just old moisture-laden fuel.
FWIW, the CEL is tied only to emissions-related things. There are lots of things that can cause driveability issues that don't illuminate the light (the afore-mentioned CPS being one of them). Also, the light doesn't illuminate automatically; there are some sensors that when they go out of range, a code is stored, but unless there are enough repetitions or combined with other codes, the CEL won't illuminate. However, you can still download those codes with an OBD-II code reader.
Were it mine I think I'd drive out the old gas, add the additive and some fresh fuel, then drive it some more. At that point I'd plug in the reader and see if there are any codes, and then go from there.
Take care and enjoy the ride,
Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy; its inherent virtue is the equal sharing of misery. (Winston Churchill)