How to find differences between environments

We are using a 3rd party to assist with AX development. Our production environment has errors that are not in our QA environment. The 3rd party has suggested moving the entire code base from QA to Production (which scares me!) Is there any way to compare the code or metadata between environments to find code pieces that might be different, or that might have been compiled on a different date? Any help is appreciated as we are new to the AX world.