Nasty afterfire...

[destrux]

I pulled my IC and ported it and installed a Greddy BOV (recirculated) and since I did that I noticed that my occasional after-fire has turned into a regular after-fire. Almost every time I shift during aggressive driving I get that nice POP out the exhaust. I know what causes after-fire..... unburnt fuel igniting in the exhaust. I don't know what is causing all the unburnt fuel in the exhaust though.

Anyone have any thoughts?

 

[MS3 GT]

what they called catted.....

 

[Huligan]

"backfire"

 

[Midnight22]

afterburn... backfire is when it pops back out into the intake tract

 

[destrux]

It's not backfiring. It is afterburn(/afterfire.... same thing). It's always been catted, and I know the cat helps make sure the exhaust ignites. I dunno. Maybe it's running a bit too rich. I should probably tune it.

 

[MSMS3]

These cars run extremely pig rich -- and need to. Even with a tune, it's downright unsafe for the engine to be much leaner than high 11 to low 12 to one AFR at WOT under load.