Are too many pops/bangs a bad thing?

[Painey]

I've got a Griff 500 with the modded back box on the exhaust. I've also got what I think is a problem with the air flow meter as I'm getting terrible fuel economy and the car is popping/banging like never before. Every time I lift slightly it sounds like a bad day in baghdad!

I'm a little worried that all this is knackering the cat and should I get it looked at? Or if there's likely to be another cause could anyone suggest what it is? I mean it's not necessarily a bad thing but I'm currently getting less than 10mpg, even when I try to take it easy.

Any thoughts much appreciated.

Thanks - Chris

[dinkel]

Wow, that's worse mpg than a VWeyron at a trackday . . . I'm not an engine-expert but maybe the timimg is a bit off. They used to set back the ignition a few degrees to avoid DFV's to pop and bang.

[GreenV8S]

Does sound like a problem, does it drive OK? Might just be an exhaust leak (this would account for poor economy and pops/bangs) but might also be that the ECU has detected a more serious fault and has gone into 'limp home' mode/

If the pops and bangs continue you will find it knocks the stuffing out of the silencers so they stop silencing, and it can also damage the cat both chemically and mechanically. Not a mega urgent 'do not drive the car' problem but worth fixing sooner rather than later.

[Painey]

The car drives absolutely fine, still goes well at least! Drove it earlier and pulls as well as ever and passed the MOT ok last week. It's just the crap fuel economy and warzone soundtrack that bothers me. Nothing else seems to be happening and like I said I'm just concerned about it knackering the catalytic converter, which I know is expensive to replace.

[Wildfire]

The thing that got me about the pops abd bangs is that the fuel that is igniting should be being used to make the car go. 10mpg is pretty bad! That's town I take it?

[mack]

Mine did exactly the same,as soon as I had the back box sleeved (the full decat prior to that,didn't seem to effect it as much)

I know what you mean though,it was getting embarrassing,it was like a 21 gun salute everytime I slowed down! :

One of Mark Adams' bespoke Tornado chips sorted everything out for me - and the fuel consumption greatly improved!

Now it just occasionally 'pops and bangs' which is more liveable

[c3ber]

You can take it from me no matter that you get the "Pops and Bangs" they are not like Baghdad on a Saturaday night or any other night.

Must admit I do not get many mpg from my Cerbera but I just put it down to living in an area where i have to change gears a lot. Will be trying to keep it in 4th to see if that helps when I get back to the UK.