My 09 G37s coupe threw a check engine light today. I had the code read at autozone and it came back as a P0420. I found a hole in the steel mesh part of the Y pipe. Could this cause the P0420 code and would buying a Stillen Y pipe correct my issue?

https://www.z1motorsports.com/exhaus...pe-p-8325.html

I was looking at the Stillen Y pipe because it doesn't have the mesh sections in it. Is this a good option or does the Y pipe need the flexibility of the mesh?

 

PO420 is a catalytic converter code bank 1 so one of your o2 sensors can be out or a bad car. Get it checked out I shouldn't be the y pipe imo

 

Also could be a vacumn leak check your Intakes check the pcv valve hose as well they rip happened to me

 

Here's my Y-pipe and no leaks, is yours worse than this???

 

My Y pipe is are nowhere near as bad as yours. I could feel air coming out of it though, so maybe it's just a small but deep cut. I'll look at the Y pipe again and check my vaccum and pcv lines today and keep you guys updated. Thanks for the help.

 

All vaccum lines and pcv lines look good. No cracks or holes that I can find. All lines feel soft and flexible. I guess it's time for diagnostics.

 

O2 sensors turned out good on diagnostic. One cat came back bad, and the other is "weak". I'm going to go with Berk HFC's as a replacement.

 

I replaced my cats with berk hfc's and found something unbelievable...

The previous owner gutted the passenger side converter, and left the driver side converter OEM.

The code seems to be cleared now. The berk hfc's paired with the motordyne xyz resonated Y pipe have a great, clean sound with no rasp. Very happy with the results.

 

Glad it's solved, and lol at just one cat gutted, maybe it was such a hassle he didn't want to do the other one or couldn't remove the SOB bolt

Those Motordyne XYZs are a nice product.