Question for anyone who removed their secondary cats or installed an aftermarket midpipe. Does doing this cause a CEL?
I don’t think it should since the O2 sensors are positioned right before them towards the primary cats.

 

It does NOT cause a CEL! There is no measurement recorded for the secondary cats.

 

Awesome, thanks for confirming. Just got them removed

 

how much louder is it?

 

Post a sound clip! Does the car still run well with the cats removed?

 

^^^^It's the secondary catalytic converters that are removed. The primaries are still in place in the OPs configuration. I'm running mine with one set of Gesi cats in my midpipe. My headers removed the primaries.

 

plz protect the innocent : is this legal to do ?

 

^^^^Depends on your location. If a visual inspection is done and the inspector knows his business, then you'll fail. If your inspection only consists of tail pipe emissions, you'll be fine. If no inspections, you'll also be fine. As far as Federal legality goes, yes it's illegal.

Note the third paragraph - How many Race Cars do you think have smog equipment

 

great answer, lou ; thanks for clearing the air ....

 

In case anyone wants to hear it!

 

Nice, now get a Intake mod. That will help flow and power a little better also.

 

How is the Cabin drone?

 

^^^^I have PPE Headers and DM Exhaust with one set of Gesi cats. There is absolutely no drone. The LC is well insulated

 

No drone, just a bit of a growl from low speed 1k-3k rpm. As sickpuppy mentioned, the LC is well insulated

 

Good to know and every car where I deleted something on the exhaust caused major cabin drone.