Re: Alfa 166 Exhaust Backfire
not that familiar with the V6 yet myself, but those symptoms would be consistent with the engine temp sensor failing, throwing in too much fuel causing it to ignite in the exhaust. I do not think the exhaust would cause the engine light to come on, but a backfire will not do the cat any good or the engine for that matter.
Best to get it hooked up to a diagnostic to see what has gone wrong to save changing the wrong bit, the part I suspect is £20 ish, at least it was on my 145 2.0 when it went. The AFM is the other candidate, but thats about £130, common failure but normally of rough running cold and warm and not revving cleanly.
My money would be on the temp sensor.