Downpipes

jeremydgreat · 06-25-2009, 01:47 AM

So, I have a sort of noobish question here. I see that many people have catless downpipes on their 135i's, yet they still seem to use these cars as their daily drivers.

Will the car still pass smog without catalytic convertors? Or do people really go to the trouble of adding/removing them every time their smog check comes up?

I'm considering doing this, but I live in CA and I'm wondering if I can pass smog check here with catless downpipes. Maybe I'm overestimating the level of effort for adding/removing them every couple years? I don't have regular access to a garage but maybe a lift isn't even necessary?

rotelly · 06-25-2009, 01:50 AM

you won't pass a smog check without cats.

But when you buy a new car don't you have a couple years before you have to worry about a smog test?

ktdw · 06-25-2009, 11:22 AM

My understanding is that with just downpipers you likely will not pass the sniff test (you would still have you secondary cats), and will definetly not pass the visual. Unless, you know a mod-friendly tester

Anyways, you have 5 years until you would have to smog a new car. I, like many of us, will likely go back to stock by then.

Installing/removing downpipes is not easy, even with a lift. I didn't do mine, but that is what my mechanic and others are saying. However, I'm sure once you have done it several times you probably could do it without a lift and in record time...like Daniel at RR.

jeremydgreat · 06-25-2009, 12:12 PM

So, it's 5 years for a new car? If it's THAT long, then maybe I'll just do it. Are you sure that's correct for CA?

Your mechanic said it was too hard to do yourself? I'd be a tad suspicious of that.

Thanks for the feedback!

My135 · 06-25-2009, 12:32 PM

If I were you, I would only do mods which I can DIY. It is just too much trouble and costly to take your car and pay some one to install and un-install. If you can't install down pipes yourself, I would pass.

06-25-2009, 01:47 AM	#1
jeremydgreat Captain 76 Rep 676 Posts Drives: 2009 135i Join Date: Apr 2008 Location: San Diego, CA (Carlsbad to be exact) iTrader: (1)	Downpipes - Basic questions So, I have a sort of noobish question here. I see that many people have catless downpipes on their 135i's, yet they still seem to use these cars as their daily drivers. Will the car still pass smog without catalytic convertors? Or do people really go to the trouble of adding/removing them every time their smog check comes up? I'm considering doing this, but I live in CA and I'm wondering if I can pass smog check here with catless downpipes. Maybe I'm overestimating the level of effort for adding/removing them every couple years? I don't have regular access to a garage but maybe a lift isn't even necessary? __________________ 135i // M-Sports Package // RR Oil Catch Can // Black Kidneys // iCarbon Hood // Alum Pedals // KW v2 Coilovers // Vorshlag Camber Plates // Hotchkis Sway Bar // Wheel Studs. Best mod ever? Tires. 255's in front, 275's in back.
	Appreciate 0 Tweet Quote

06-25-2009, 01:50 AM	#2
rotelly Private First Class 2 Rep 144 Posts Drives: 135i Join Date: Apr 2009 Location: seattle iTrader: (1)	you won't pass a smog check without cats. But when you buy a new car don't you have a couple years before you have to worry about a smog test? __________________
	Appreciate 0 Quote

06-25-2009, 11:22 AM	#3
ktdw BMWCCA #401908 54 Rep 470 Posts Drives: 135i Join Date: Apr 2008 Location: Bay Area iTrader: (0)	My understanding is that with just downpipers you likely will not pass the sniff test (you would still have you secondary cats), and will definetly not pass the visual. Unless, you know a mod-friendly tester Anyways, you have 5 years until you would have to smog a new car. I, like many of us, will likely go back to stock by then. Installing/removing downpipes is not easy, even with a lift. I didn't do mine, but that is what my mechanic and others are saying. However, I'm sure once you have done it several times you probably could do it without a lift and in record time...like Daniel at RR. __________________ Vishnu PROcede v3, Vishnu Dual Cone Intake, Code3 FMIC, Riss Racing Downpipes, Riss Racing Exhaust, H&R Sport Springs Best 1/4 mile: 12.583 @ 117.609 mph
	Appreciate 0 Quote

06-25-2009, 12:12 PM	#4
jeremydgreat Captain 76 Rep 676 Posts Drives: 2009 135i Join Date: Apr 2008 Location: San Diego, CA (Carlsbad to be exact) iTrader: (1)	So, it's 5 years for a new car? If it's THAT long, then maybe I'll just do it. Are you sure that's correct for CA? Your mechanic said it was too hard to do yourself? I'd be a tad suspicious of that. Thanks for the feedback! __________________ 135i // M-Sports Package // RR Oil Catch Can // Black Kidneys // iCarbon Hood // Alum Pedals // KW v2 Coilovers // Vorshlag Camber Plates // Hotchkis Sway Bar // Wheel Studs. Best mod ever? Tires. 255's in front, 275's in back. Last edited by jeremydgreat; 08-23-2009 at 01:25 AM..
	Appreciate 0 Quote

06-25-2009, 12:32 PM	#5
My135 Lieutenant Colonel 85 Rep 1,609 Posts Drives: Join Date: Mar 2008 iTrader: (0)	If I were you, I would only do mods which I can DIY. It is just too much trouble and costly to take your car and pay some one to install and un-install. If you can't install down pipes yourself, I would pass. __________________ 7/08 135 Coupe, Crimson Red, 6 SP, Sport, Taupe Lette/Aluminum. Performance Mods: JB4 on Map 5, BMS DP Fix V3, Injen polished intake, AR Catless DP, Maddad resonated mid-pipes, aFe exhaust polished tips, ST Suspension Coil Over and Hotchkis front sway bar. Others: BMS OCC, BT Scanner, Mud Flap. Next Mods: AA Front Strut Brace.
	Appreciate 0 Quote