I think the Bonez unit is of decent quality, but mine only lasted about 40,000 miles before the car wouldn't pass emissions anymore on a mildly street ported S5 NA. (After getting a new cat, it passed again with flying colors.) Don't know if this is the best you can hope for from an aftermarket cat, but it's a lot shorter lifespan than the stock cats.

 

ok so now i have a question for you. a bonez high flow cat that doesnt pass smog anymore, does it still eliminate the exhaust fumes? im guessing it does just not as well as new?

if in fact it does still eliminate/reduce exhaust smell compared to a catless setup, i'd be interested in buying a used bonez to use as an alternative mid pipe just in case i cant stand the fumes

 

Nothing special about the Bonez cat. I would recommend one of the Magnaflow universal fit cats.

 

Yes, it still eliminates the vast majority of emissions, just maybe not enough to pass California smog. I'll have two used main cats (one with the line for the airpump) within the next week. I'm not sure if they're Bonez or not, and they're the size of the stock N/A piping. I got them new several years ago from RR&R in Santa Ana, CA, a reputable rotary shop.

The reason I went with a Bonez for my current build is so that I can connect the line for the airpump and clean up my emissions drastically.

 

PM me about your leftover cat with the air pump line, wanting to know what size piping

 

here's a teaser of my exhaust setup so far:

 

so today came upon seeing 'spun cats' from magnaflow. anyone have any expiereince with these? just to remind you, im using 2.5" piping so i would want a 2.5" in/out sized cat. Exhaust flow is key, but looking to reduce exhuast emissions vs catless. heres the link, let me know:

http://www.car-sound.com/02product/u...al/599spun.asp

 

I have one of those. 3" inlet/outlet on my car, and a cat with air tube after it. What do you want to know?