2002 Problem

I just talked to my mom and it seems that her 2002 Dodge Ram quad cab(4.7L) has a problem. When the A/C is on she says its like the engine has to work really hard, AC off it drives normal. The check engine light came on the day this started. Any ideas?

Codes?

retreive your codes:

http://www.allpar.com/fix/80s-codes.html


You'll have to look for the right page for a 2002, but it's covered in the link..