Gurgling engine?

[tiessen]

When I'm climbing a steep grade at low speed, and low RPM, sometimes I hear a gurgling/rattling sound. Sounds like it may be coming from the cat? How do I tell if my cat is gone or what else should I check? Power seems OK, no hesitation, stalling, etc. Bad gas mileage but what do you expect with 6" lift and 33's.

Thanks in advance.