Magnaflow Cat: 23909 vs 49150
 

Any reason to order the $600 Euro-4 version over the $300 Federal version? I understand that the Euro-4/California version has lower emissions, but I only care about passing the OBD2 test and durability. I am just looking to get a couple more years from my stock '04 commuter RX8 with a currently dead (or dying) cat.

TIA

I have the 49150 and it's held up well almost 2 years old, it is not CA complaint to my knowledge my friend has the 23909. The 23909 the O2 sensor hole is in the wrong spot fyi.
Looking at them side by side the only difference I see is over $300.
It should work for what you need not saying this is your case, but alot of cats fail because people don't stay on top of their ignition system.
Good Luck

I went ahead and ordered the 23909 version before your post.

I did not install it myself. I took to my local garage and had them install it. They said it bolted in fine, no comment on any issues with the O2 sensor. Either they fixed the 23909 version or (as an earlier post on a different thread indicated), the fitment issue might only pertain to AT vehicles. Mine is MT.

50 miles in it seems to be working fine.

This is an update I have the 49150 CAT and pulled it down to look at it after getting the dreaded p420 code the other day.

It was completely hollow looks like it was made that way. Only thing that was visible was the o2 sensor no evidence that a honeycomb ever existed. Apparently it exited on its own don't know exactly when.
My point was if you need a CAT that is going to last and pass emissions don't buy this one. I have a new banzai rebuilt engine and ignition system with a Borla catback and it only lasted 13k (when CEL appeared).

They sell #23909 (looks exactly the same as #49150 setting side by side, #49150 is supposed to be OEM quality according to website.....bs!) for @$300 cheaper my friend has the 23909 and on its 4th year buy it instead.
I'm not mad saved me gutting it if it was bad.
So now I basically have a magnaflow midpipe and a CEL that will never go away still better than losing a engine to a clogged CAT.
Rev'em high and often friends!!!!