For some reason the car seems like its calmed down on the pops, banks and crackles front. Its burbling a lot but not producing the bangs its used too. Even when feathering the throttle. Every now and then you get a good crack but nothing like before??

Only clue, is I've just fitted a 2nd hand Quicksilver exhaust/muffler. When it first went on and we revved it up, the cracks sounded like gun fire! Sounded great! And when I first drove down the road. But by the time I got home, 6 miles or so, it definitely started doing it less. The vacuum lines to the valve control on the OEM exhaust, they blocked those off. Can't see why they'd need to breath?

It does ring a bell that someone else had this problem and solved it?? (not related to an aftermarket exhaust/muffler I don't think)

Its a 2013 V8.

 

Prophizee has the quicksilver if you want to PM him. He said it got louder after the insulation and **** burned up. Now it's raucous.

 

This is a used one so it’s done all it’s burning up. Someone on another Forum said he has a similar problem that was solved with a new o2 sensor. Wonder if exchanging the exhausts disturbed it / damaged it? They did have to sack it quite hard to get the oem one off, perhaps the shock killed the sensor?

 

I lost most of my pops and bangs. No fault codes in display. Had the workshop read out any fault codes in the system, and it came up with two faulty O2 sensors (they had not stopped working, but gave wrong readings).
Replaced sensors and drove it for a while so that the engine management system could "recalibrate". Pops and bangs back to normal.
Reason for faulty sensors on my car might have been the application of a anti-corrotion coating on the underside done without good enough covering of the sensors.