New Trans and now OBD code p1131

Does anyone think this code came up because of replacing the transmission? What would you recommend doing to clean this code out?

Anything is possible with that kind of code. Since it is saying you have a lean condition coming right out of the engine, and you just moved everything around, you very well may have a vacuum leak somewhere. Beyond that, I suggest perusing some of the other posts here that might seem relevant by using the Escort search. This thread I think has very good info and saves me some typing.:)
http://www.automotiveforums.com/vbulletin/showthread.php?t=890652

Just a thought: If it's an automatic tranny did you hook the vacuum line back up?

It isn't always recommended to do it this way, but disconnect the battery negative terminal for 15 minutes and it will clear out the code. If the code isn't ongoing it should clear it out. A one time code not ongoing will clear itself out after a series of starts and stops. This does it automatically in a much shorter time span. If it is ongoing the light will come back on.