I have a 2004 Bonneville with 57K on it, I've racked up about 36000 on the old Odometer since a bought her last April.

Since the first day I've owned the car, it has the tendency to intermittently stall when shifting from drive to reverse. Sometimes it would act like it wants to stall but then catches itself (RPM'* drop from 800 down to 3-400 rpm'* then recovers). Other times I can drive it for thousands of miles without it stalling once. I've had the MAF sensor replaced and the lower intake gaskets replaced during my last visit at the dealership. They figured that this would take care of the problem. (It didn't)

Any suggestions about where else I should be looking?

I'm no transmission expert, but I suspect the torque converter could be at fault. There are many different things it could be. Wait for another reply... just putting my two cents in.

I don't suspect a trans problem. I suspect the motor bogging down, and the lower gear taking it'* toll.

I'd be looking for a vacuum leak.

your front motor mount might be adding to the problem. Does it do it from Reverse to Drive? I agree with a vacuum leak.

Hmmm 57k on it. About time for new plugs and wires?

I thought about new plugs and wires but it did this when it had 21000 miles on it and it does it every once in a while ( I can count the number of times that it has happened to me on one hand). It'* just that I've never owned a vehicle that has had this issue and it'* annoying me.

I vaguley remember that my PCM needed to be reprogrammed to fix the problem. I can look tonight when I get home if you would like.

I'd start with the Battery cables and grounds. Clean, apply dieelectric grease then reinstall.
then remove the ICM connector and do the same while tightening up on the connector sockets. Finally do the same for the intake sensors. Remove the IAC and clean it.
Let us know how it goes.

Get your air idle valve cleaned.
Happened to me, the guy (who has it today) fixed it and ive never had that probelm since.

The problem happend first around 93000 miles and now with 116,000 on her..shes runnin fine.

Hope this helps

Ponch 04

Ok I found it. These codes do not make much sense to me but I am sure a gearhead will chime in.

Calibration History for: Control Module
Part Nimber: 12594007
Cal. ID#: 12594009
CVN: N/A
Bulletin #: 0
Description: New calibration to correct potential stall when shifting from drive to reverse under a power steering load.

Hope this helps.