Hi guys

First some info
Oldsmobile cutlass supreme 4 door 1966
​​​330 v8 th200-4r
dual exhaust

Last week my car started popping from my exhaust when i let go off the throttle at 3000rpm or below.
it got worse and worse the more i drove the car. And now it popping from the exhaust when i let go off the throttle at any rpm. The sound does seems to come only from the driver side exhaust. (I have true dual exhaust but without a H or X pipe or something like that)
it driving me mad. The car does drive fine and runs perfectly. Does not mis and has all of its power.
i checked all the plugs and they are fine. All cilinders are firing just fine

A couple friends of mine think my exhaust manifold is leaking somewhere. Can this be true? I did not have time to check yet.

i tried to film the isue but i can only upload the audio, i hope you guys can hear it and help me?

 

I agree with your friends. You have an exhaust leak that allows oxygen to mix with hot exhaust and ignite un-burned fuel. The leak(s) may be slight and hard to hear/pinpoint. Have a helper hold a big wadded up ball of rags over one tail pipe at a time. With the engine at idle speed squirt a couple shots of engine oil in to a small open intake manifold vacuum source. The resulting smoke will show up any leaks.

 

An alternative would be a Smoke Machine inserted into the tailpipe.