2000 nissan altima CEL (check engine light) 2.4l

[dsmtuner1]

Hello, My check engine light came on today and when I took it to Autozone it said "air fuel meter". Car seems to run fine, but I have noticed some extra sut on the rear bumper, might be running a little rich.

Has anyone had this same trouble code and what is a fix for the problem. If anyone has a link to the codes and what they mean that would be great as well.

I think it might mean somethings wrong with the MAF, and they are way to expensive for me right now, so if that does happen to be the problem is there a fix or a way to clean them properly?

2000 nissan altima 2.4l.