Can a leaky muffler ? (rusting/lil hole in it some where) cause this code to come on? Or is it more likely just a clogged EGR tube? I have a 97

 

search, thats one of the most common codes for our cars

 

No, a leaky muffler will not cause this.

99% of the time this code comes up because of a clogged EGR guide tube. It can be removed and cleaned and the code should go away. You can find a How to on this under the 4th gen How to's thread. Good luck.

 

Had that code two days ago, removed MAF tp inspect EGR lines and found the line at the bottom of the EGRC-BPT valve had somehow melted. Replaced the hose, it was about 1.5 inches long rest the CEL, and the code is gone. Other than a major component can also be a vacuum leak, I was lucky to find it before i started replacing components, maybe if you know someone with a smoke machine also that can help check your vacuum lines.