ERG & MAP giving me hell

All right I just replaced the thermostat housing and the vac switch. Now I'm getting a code 5 for the map. I had been getting a code 12 for the EGR but hadn't got around to cleaning it yet. Here's the problem when the PGFI light comes on it runs fine. When the light doesn't come on it runs like shit sputters and dies if I let of the gas, not fun in traffic. I check the vac lines and they're all attached. I priced a new map from Napa $335 bones. Any help would be great so I don't have to drop the coin on a new map.
Thanks Keith

get one free from the junkyard.

or check the pipeing. ive rarely seen a map sensor die. make sure pipe 21 is hooked up

Thanks The yard was slim pickin's when I was there last but I was going to give it a try first. The piping is in place and looks good.

Any other Ideas