5.2 355 going into limp mode intermittently....

OK, I've got one for the brain trust....

My '97 (hence, 5.2) 355 began falling into limp mode a few times over the past week. First time was after driving for 40 mins without incident, parking it for 20 mins, then starting up again. It cleared after about 15 seconds and did not return again that evening.

Yesterday morning, it went into limp mode upon cold startup. It ran like that for about a minute then the engine came to life and drove normally. It went back into limp mode after an hour of normal mixed driving as I was parking the vehicle for the night. Upon startup today, it fired up normally but went into limp mode again after 15 mins of driving. This time it stayed in limp mode for several minutes. I pulled off the freeway, tooled around surface streets trying to see if the engine would return to normal. It finally did and I drove it straight home where it sits now.

Some backstory. Many of you are already somewhat familiar with the saga of this particular '97 355 Spider. I've had CELs since I acquired the vehicle and, although many of these have been iteratively addressed, I still have at least one (and will continue to get at least one) as long as my aftermarket exhaust continues to have no bung for a thermocouple probe. I need to have one welded in from an exhaust shop, I just haven't had time to address it.

However, even with that CEL the car has been driving fairly well. No SDLs, etc. Until this past week.

You should also know that in the past 6-9 months I have replaced the thermocouple ECUs, the 02 sensors, and the plugs. So those should be eliminated as culprits.

I pulled the codes and I'm getting:
1128
1448
0410
1454

Any thoughts on where to look now and what I can do to resolve this? I want to be able to make it down to Pete's for the Stoogeapolooza this wknd, so time is getting short.

Thanks all.

ketel