Pops and bangs

[mgbond]

I had a back fire last week and sounds like its blown a gasket joint on the exhaust. Since then (goes in for a service next week so was going o get it sorted then), often after lift off I will get a bang or two. (Car does run a bit rich)

Could it be that the now hole in the gasket sucks in air to the exhaust and mixes with un burnt fuel and ignites.

Or is something else up?

Bondy

[D_G]

Mine used to pop a lot on the overrun, since Yellowshed mapped it the pops are much reduced. You still get a little bit especially if you slow down in gear from 3k but never had a full backfire though.

[mgbond]

D_G said:

Mine used to pop a lot on the overrun, since Yellowshed mapped it the pops are much reduced. You still get a little bit especially if you slow down in gear from 3k but never had a full backfire though.

Mine is only since blow in exhaust

[ultimaybe]

Just a possibilty that someone else will need to confirm or shoot down:
Is there a lambda sensor in the exhaust? This might be seeing more Oxygen than it should and forcing the mixture to richen up?
Might then cause backfire.

[mgbond]

ultimaybe said:

Just a possibilty that someone else will need to confirm or shoot down:
Is there a lambda sensor in the exhaust? This might be seeing more Oxygen than it should and forcing the mixture to richen up?
Might then cause backfire.

Mine is an after market ECU and I do have a wide band lambda on one bank. All is well on that front. Bumbled into my old mapper at goodwood today and he confirmed that if an exhaust gasket has gone then pulling air into the exhaust will cause these pops. As its only started since the blow in the exhaust it must be that.

Will see when the gasket is replaced.