does a 2001 duramax have Cats?

[mattfarmer]

Hey guys,

I apologize if this question has already been asked, I'm not very good with computers and never have luck finding things online...

I have a 2001 duramax, runs well, barely smokes even when I'm pulling heavy farm equipment around.

I don't remember this truck aving a cat when I put a MBRP 4" exhaust on it... I can't find my factory "front pipe" but know where my rear section is, am I screwed in california for smog? My intake is factory and I DON'T have a chip


thanks,
matt

[kaylabryn]

No to my knowledge and all of my reading in 2001 none of the Dmax's had cats, and only some 02-04's have them. Most do not.

[DmaxMaverick]

No cat, unless you left the window down. They started in CA (CA smog) on 2002 models (along with EGR).

Mine passed easily with a 4" exhaust. If you aren't blowing smoke under mild throttling, and the SES isn't on, it will pass. They don't sniff the pipe, either (they only "look" for excessive smoke). The smog computer will tell the tech to look for whatever parts, if they're supposed to be there. Friends with later models said none of the techs looked for one on their later models, although most have (had) one. They did do a visual inspection of the EGR components, but no actual test. Make sure you don't have any tuners or programs installed during the test, or it could fail.

[mattfarmer]

Thanks a lot for the help, is there anywhere on the vehicle that would say it didn't come with a factory cat?

This whole diesel smog thing really has me worried, I bought a diesel truck both for it's towing ability and (back then) no smog crap.

[DmaxMaverick]

There is nowhere on the truck that says it did not come with a cat. If it had one, there would be a sticker showing that it did. Much the same as the computer you are using, doesn't have a sticker saying it doesn't make coffee. The emission sticker is under the hood, on the radiator support cover. For 2001 (I have one), all Duramax equipped trucks were the same, in regards to the emission requirements, coast to coast. CA emissions (cat and EGR) began with model year 2002. If it isn't smoking and the SES isn't on, don't worry. Pay the extortion.

[mattfarmer]

SWEET! thanks for the help, I just got my papers the other day and I've been going crazy trying to find my stock "front pipe".

My truck doesn't smoke and if "SES" is in reference to "service engine soon" ...I don't have that light on.

[NutNbutGMC]

...... and if "SES" is in reference to "service engine soon" .....Correct............

[DmaxMaverick]

I have 2 front pipes. The original from 2001, and one from a 2004 LB7, with cat. There's a lot of pipe-switching going on around here, and mine are always on "loan", with an adapter so a rear 4" (or larger) pipe doesn't have to be removed to be "CA Legal". Not that I advocate emission system modifications. This is for "off highway use only", of course.

[mattfarmer]

thats a great idea, is there anyway you could send me pics of your "road use" front pipe so i could see where the cat goes... I found an 04 exhuast a few hours north of me in marysville, so I might make a setup like yours...

thanks

[DmaxMaverick]

I can do that, maybe later today. You won't need the pipe/cat for your 2001, in any case.

Where are you located? If you're a few hours south of Marysville, you're a couple hours north of me.

[mattfarmer]

I'm between Fresno and Merced in a little farming town called Le grand... the people around here are pretty cool about all this smog non-sense but I'm just worried about getting some tech who's in a bad mood.

my dad has a 98' 6.5turbo with 52,000 ORIGINAL MILES.. IT DOES NOT SMOKE.. and this jerk that was supposed to inspect his truck just kept making up reasons