I have a UK 2006 1.8 Honda Civic ES and a noise from the exhuast has been starting to annoy me recently. When i start the engine and put the heater on a weird gurgerling noise comes from the exhuast which seems to get louder. Ive never had a problem like this with other cars ive owned, so i wanted to know everyones opinion on it. I took it to a local honda service place and they told me that it occurs when the car drops revs when the aircon is on and thats the reason for the noise but i think theres more to it. PLEASE HELP!