Yeah maybe. Thanks for the suggestion. Just seems weird how it's all of a sudden.

Could be the baffle has come away from outer casing, iirc they are only spot welded in place, though could be wrong?

If you go back to the supplier he may well say 'they all do that, sir' ??

I do not know what the whooping noise might be but go along with the theory of loose baffles.

I would like to mention the ever more common practice of cars emitting popping noises and loud bangs from exhausts. This is prevalent on many more modern cars and it appears some manufacturers offer it has some optional extra? Not very clever when you are walking the pavement with your dog.

I do not know what the whooping noise might be but go along with the theory of loose baffles.

I would like to mention the ever more common practice of cars emitting popping noises and loud bangs from exhausts. This is prevalent on many more modern cars and it appears some manufacturers offer it has some optional extra? Not very clever when you are walking the pavement with your dog.

It seems to occur when boy racers thrash their sporty cars to the rev limiter and then lift of and brake. (Seats seem to be a popular choice, being cheaper than the equivalent Golf.)

Valve timing and overlap must play some part in these events, on modern cars valve and ignition events don't change much from factory settings, unlike the old days of contact breaker distributers and carburetted mixtures.

More likely imo it has a straight through exhaust as I`m not so sure a back box will make it much louder, possibly make it sound like a V6 but thats about it, a full system will but not part, ie rear silencer, on re reading whats been said I think its a full system which may not have been tried out fully beforehand hence the surprise in sound difference

I could be totally wrong ????

There's no reason at all for modern vehicles to backfire through the exhaust.

One of the cars I looked before deciding on another Superb was the Hyundai i30N, thought that a last "hot" hatch might be a good idea before senility finally sets in.

That car had various settings some of which made it pop and bang on the over run. For me it was not desirable, every time I hear such a sound I think "winker".

No idea if its possible to stop it banging but close to us on old bloke (must be in his 80's) has an i30N and that pops and bangs a little as he lifts off, not enough to frighten children but its still there.

The only exception would be for turbo charged, high performance vehicles requiring exhaust gas to keep the turbo spooling and advoiding lag

The need for injecting fuel directly into the turbo to keep it spinning ceased many years ago. With modern electronic management its simply not necessary.