What is the box in front of the coolant recovery tank called and what does it do? Would it being broken cause the check engine light to come on and affect fuel economy?

 

Oh, and it´s a 1998.

 

It's the ECU box for the car and tranny. The box doesn't do anything except hold the computers and there is a tube that goes to it to help cool it.

If you have a CEL, you need to connect a code reader and read the codes. The port is in your arm rest. Once you have the codes you can post them here or figure it out from there. And yes things that pop a CEL can effect your gas mileage.

 

The code reader didn't find anything, so I was wondering if it was possible that the box being broken might be frying the computer.

 

If there was not code why is the light on? Reset it and see if the light returns.

Tape the box up or something. I believe it's designed to keep the computers a little cooler but I don't think it would be easy to change.