[ImperialCrown]

Welcome to Allpar. Maybe poor connections at the PCM or sensors. Sometimes removing and reinstalling a connector will wipe the terminals enough to re-establish a good connection.
Some of the codes may be related to something shared, like a 5 volt sensor supply voltage and could set multiple sensor codes.
Have you tried erasing them and seeing which ones come back?
The P1391 is scary as some flexplate cracking issues could cause this code. There is no real confirmation of this other than removing the transaxle for a visual inspection.
Get ahold of a factory service manual with diagnostic and wiring information to help you.

 

[Doug D]

Cracked flexplates are a somewhat common issue with the Gen III's. Discovered the flexplate was cracked on our former '00 T&C Ltd AWD (3.8L). The symptom in our case was a marble like rattling coming from the AC compressor when the engine was at idle. In reality it was the flexplate cracked in a jagged circle around the mounting holes with the sound of the flexplate cracking going down the crankshaft and exiting via the AC compressor. Never got a CEL light. Ended up costing $550 to repair. Only $67 for the flexplate - rest was labor cost. IC is correct - visual inspection is the only way to confirm.

 

[ImperialCrown]

Sometimes there is no noise at all. Sometimes months go by before the code sets again.
A dual-trace scope watching the cam and crank sensors together will sometimes show a waveform that 'walks' around a little because of the flexplate 'float', but a worn timing chain can also 'float'.

 

[BlackSheep01]

not having access to a code book, I'm going to make a few guesses based on living with old Mopars.

Rough running might be a stoppage or possible stoppage in the fuel lines, the fuel filter, junk in the
fuel pump intake or the fuel lines, a bad or dirty injector, or bad connexions to the plugs / distributor.
Or a vacuum leak. Or a clogged catalytic converter. A timing chain that's off or a timing gear that's
worn can throw things out of kilter, too. It could also all be some sort of electrical malfunction that
might be throwing codes over/above the actual problem (s) :frustrated: .

 

[chuzz]

Since it sat for quite a while, I'm going to suggest you just go through the harness and clean every connector you can find. As we all know too well, any type of corrosion can cause a multitude of problems. I'd start with the battery cables and work my way through the entire engine harness if it were mine.

 

[gearhead2578]

Sounds like another bad alternator. Test voltage at battery with engine off, then with engine running to determine if battery and alternator are good. Also check at alternator B+ post. Low voltage will cause all these codes and insufficient voltage will cause rough running. Just because it charges some at idle doesn't mean there isn't a bad diode in the bridge rectifier causing a discharge above idle while driving. In 20+ years in the shop the best thing I've learned is not to overlook the basics. Interpretation of symptoms is best done as a whole instead of focusing on each individual code - 9 times out of 10 it's one problem causing the whole mess.

Just my $0.02

 

[ImperialCrown]

Re-reading the Freeze Frame data that you provided for P0117, I see an engine temperature of 260 deg F. The RPM is 0, so I would say the code was set with the engine off.
This could be heat-soak or overtemp. Check the cooling system. Does this vehicle run hot otherwise? If not, this could also be electrical at the engine coolant temperature sensor (ECT).
If each code set a freeze frame, this would tell us the conditions under which each was set and help diagnosis.

 

[BlackSheep01]

Concur with rechecking major electrical components -- a bad battery / weak alternator can wreak havoc with other electronics / electrical systems and computers.

 

[gearhead2578]

As can a bad engine to body or battery ground!!

 

[BlackSheep01]

and a bad ballast resistor, come to think of it ...

 

[AC TC]

Bad gas? Gas gets old these days....for a snowmobile it only takes one short and cold swedish summer!
-have you poured some fresh gas in it?