I have 3inch piping with flowmasters for exhaust, not sure if it is CAT back or not.
The engine size is the v6, on the 1987 base line model.
Sometimes when I shift around 3k RPM I hear a load pop, not quite as loud as your normal backfire and there is no smoke.
Any ideas to what the problem could be? my friend tells me its just my exhaust rattling but it sounds like more and usually only happens around 3k RPM.

Thanks.

 

Well, a rattle and a pop are 2 different sounds. Flows are know to make a popping noise upon letting off the gas. However, it could be a backfire, do you have an exhaust leak? And, how come you have 3" piping on a V6?

 

When I bought the car it came with 3inch piping and the flowmaster, with dual tips.
I am not sure if I have an exhaust leak or not... not quite sure how to check.
When I shift I let off the gas so it must just be the flowmaster.

 

well one way I found a few exhaust leaks on my car was to let the motor soak in ATF over night
started it up and let it ran for a while
trust me that stuff smoked for like 15 min after I did it
though I do have a diff engine design then you guys but I am sure you can still get it to work



for the most part if you have a leak you will se white smoke just pouring out like crazy

if you do this I would say watch out how much you put in dont want to hyrdolock anything

 

An exhaust leak sounds like a ticking noise, I'm sure one to cause a backfire would definately be noticable, and it's directly related to engine rpm.