Check Engine Light

[skyscraper]

Any ideas on what could be causing my check engine light to come on when its cold out on my 1995 540. The car runs good off idle but as soon as you put it in drive when the temp is below -5 c the check engine light comes on and the car goes into limp mode. As soon as the outside temp goes above -5 the light goes out. I've replaced the o2 sensor but no change. I've tried to get it into the dealer but they can't look at it until the end of December.

[632 Regal]

search intake leak or vacuum leak, very common on the V8s.