Do all Duramax have cats???

Yea I Heard Some Of'em Have Dogs Too Bully Dogs

2004.5 and up LLYs have cats. I have heard of some early LLY(s) not having them from the factory. I lost mine a few months ago.

Then my next question would be would the down pipe make any difference on my 02 if I didn't have a cat????:confused:

you don't get an actual downpipe


the aftermarket mis-informs you...you get a downpipe back exhaust...

Yes you would make a difference..going from a factory 3.5in pipe to 4in.

Yous get the turbo to spool quicker and lower egts....no horsepower really.(do a search)

Now, TTS did just come out w/ a actual downpipe for the Lb7...i dunno about gains..but its should be free'er flowing and lower egts

Then my next question would be would the down pipe make any difference on my 02 if I didn't have a cat????:confused:

on your 02 the only difference would be the stock pipe is 3.5" and the new pipes are 4" so no not really.

Do all Duramax have cats???

My lb4 had no cat (bought it in Texas.) I think it depends where you buy your truck. I'm almost positive if you buy one in California it will have a cat.

this is true..some pre-LLY motors did have emissions installed and California is a prime example of where those would be.

Briano...i thought the 4in gave lower egt's?