gas cap light keeps coming on on 1999 Cadillac Catera

I have replaced fuel cap, tank pressure sensor, checked all connections. Worked for a few days and the light comes back on Car loses power when this happens

1 answer 1 comment
This is a pretty large subject. Here is an article I wrote about for 1 of the more common Evaporative System Codes and there are several. What is the Check Engine code and please be specific.

http://repairpal.com/OBD-II-Code-P0442
There is no check engine light that comes on. There is a fuel cap light that comes on. The transmission seems to lose the first two gears when this happens