Car Backfiring After Extrators installed

[angusis2fast4u]

About a week ago i installed a new cat back system to my na6 and it didn't change anything (in regards to backfiring). yesterday i installed extractors and on deceleration the car now backfires. they aren't extremely loud backfires but are noticable. During the install i reused the old o2 sensor.

What could be wrong?

[hks_kansei]

How big are the backfires? gunshot style, or just a light popping and rumbling on overun.

MX5's run fairly rich standard, and can tend to make a few rumbles and pops etc when you give the exhaust the opportunity.

Mine has OEM headers, OEM midpipe (inc OEM resonator) an 80cel cat, and a straight through muffler.
Cold overun it rumbles and pops and carries on, when hot it will make decent bangs during a gearchange.
And also when hot if I tap the throttle I can get it to make a pretty good whipcrack.

[fastfreddygassit]

air leak from a gasket (flange, manifold, etc) not sealing properly?

[angusis2fast4u]

As long as it's rich not lean haha
It's just little pops not anything like a gun and only on deceleration that I've noticed.

Also gaskets are new and tight :/ shouldn't be

[manga_blue]

If it's backfiring into the intake manifold then it may be indicating an exhaust blockage. Backfiring into the exhaust is pretty common with our cars - rich mixture usually.

[ralt]

Hi.
Do you have a resonator in your system? If you have you should not have any pops etc if no resonator you will have them.

[project.r.racing]

Hi.
Do you have a resonator in your system? If you have you should not have any pops etc if no resonator you will have them.

wrong.

[sailaholic]

Agree if got a resonator and muffler and I get pops bangs a plenty.


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[NitroDann]

+2.

[brendanstacey]

For diagnosis,

Backfire = Ignition in Intake
Afterfire = Ignition in Exhaust

You have Afterfire.

[angusis2fast4u]

For diagnosis,

Backfire = Ignition in Intake
Afterfire = Ignition in Exhaust

You have Afterfire.

Thanks for clearing that for me, never knew the difference, yeah definitely afterfire

Hi.
Do you have a resonator in your system? If you have you should not have any pops etc if no resonator you will have them.

Nup no resonator, high flow cat and muffler only

[bruce]

I'm a bit like that after a can of beans...

[hks_kansei]

Nup no resonator, high flow cat and muffler only

That'd do it.

It's pretty normal, I wouldn't be concerned.

[angusis2fast4u]

Nup no resonator, high flow cat and muffler only

That'd do it.

It's pretty normal, I wouldn't be concerned.

Thanks HKS

[TurboDoseBro]

If you can get flames to shoot out I want part in this!