Sunbird Sputters(Please Help!)

1988 Sunbird 2.0 4cyl. Here's my problem,when it's cold it sputters and shakes terrible until it warms up then it seems to run fine.I have installed a new map sensor and cleaned the EGR valve,ran good till cold weather hit,and it also seems to rev engine more when i put the brake on to put it in drive.Showing no eng. codes.I appreciate all the help any of you can give me.TIA Bobby