I just spent some time going through the thread about the Modified OEM Muffler (drill mod) and found it to be pretty interesting. Certainly a cool, cheap mod during the time between having a stock exhaust and going to an aftermarket exhaust.

Have any of you guys done this mod as well as a cat delete?

We don't have emissions here, and I have FVD software, so I shouldn't get the O2 sensor code, nor will I get in trouble with the inspection.

I was planning to have my two cats hollowed out and then depending on the sound after that, I may also do the OEM Muffler mod.

Any feedback? What kind of gains are guys seeing by gutting out the entire cat? I saw where the OEM Muffler mod helped produce 10-15whp, I assume the addition of hollowed cats will also add to that number, yes?

Any feedback would be cool,
Thanks

 

BTW, does cat delete causes any health hazard??

 

Nope, not unless you sleep with your head right at the exhaust tip then you may have health issues... But if you mean like health issues with it getting into the cabin then no not really, it's not a big issue, I didn't have problems with that in my other catless cars... You could sometimes smell it at a stoplight, but that was it

 

the oem muffler has 4 cats inside (2 on every side), i drilled out the second cats a few years ago.....i feel no increase of power.....if you hollowed out all 4 cats you have a increase....or you change it with 2 100cell....

 

Call S-car-go and talk to them....

Jeff

 

Where are the other 2 cats? I know there are two primary cats right behind the turbos that actually bolt to the turbos, but are the other two inside the muffler system itself?

 

Do you need to tune the ECU again after cat delete?
I recently removed the 2 x 200-cell cats from EVOMS muffler and feels some unexpected power drop.Turbos did spoll faster and nosier than before but car not as quick as before..Should I tune the ecu again?I have a 997tt with EVT700 setup.Can't really figure out why is that happend..Pain~~

 

Yes, no dubt, reflash it.

 

Interested in seeing pics of modified stock pipes.

 

yes behind the cats after the turbos there are cats /greater cats this is wy the oem muffler is so heavy

 

I was considering doing two cutouts on the exhaust, gut the first cats and install exhaust cut-outs right there - so I can open them right after the turbo, and the exhaust will just dump, instead of having to go through the muffler and the secondary cats as well.

Think that'd work?

 

yep me too

 

Any update on this?

 

Any update on this?

 

I have the drill through mod.. TJW mod IIRC..