my 3.2 backfires after installing the test pipe and K & N

[john walker's workshop]

all cars burble (backfire) thru the exhaust on deceleration. the cat was basically a muffler, and now it's gone. no mystery.

[Joe Bob]

Burble...that can be from carbs and less muffling....LOUD BANGS are exhaust leaks, like Superduperman said....

[john walker's workshop]

REALLY?

[pbs911]

I've never had a backfire with my 3.0, with a cat pipe or pre-74 exhaust. Purhaps a little burble as John said, but I've never noticed.

[CamB]

I agree it is possibly normal.

I replaced the cat on my Peugeot 106 with a straight bit of pipe and the 3 box exhaust with a straight through one.

As the insulation in the exhaust wore out I would get fairly major popping and burbling on a trailing throttle at low RPM. I would also get a fairly aggressive pop/bang at high revs changing up.

And that was from a piddly 1300cc (about 110hp though from 8 valves).

Cam