Secondary cat delete N53 3.0i

styler · 08-07-2013, 09:30 AM

Hi Guys,

I have searched the forum regarding secondary cat delete. Most who have done it say there are oxygen sensors upstream and downstream of the primary cat.

I have a oxygen sensor just after the secondary cat also. I want to remove the secondary cats, but i'm not sure if in doing so will throw up emission error.

Thanks in advance.

BudVlad · 08-07-2013, 11:34 AM

I removed secondary cats by installing Supersprint catless exhaust with O2 sensors. It didn’t throw any error and I passed sniffer test with no problem.

styler · 08-07-2013, 02:27 PM

Cheers bro. Good to hear. I have custom dual exhaust with no resonator or muffler. Still not loud enough, get a bit of low end boom but not much after 4K revs. Looking to make it scream a bit more.

SDemetris · 08-07-2013, 09:36 PM

Got rid of mine with no problem. Just had an exhaust shop weld in some straight piping. But I must have a different setup because i have no O2 sensors after mine

Phil325i · 08-08-2013, 04:14 AM

OP be aware that the UK MOT test now requires all factory-fit emissions devices to be in place. So while your car may pass the emissions test, the absence of the cat could be a mandatory fail...

Rival · 08-08-2013, 08:30 AM

if you have an o2 sensor after you will throw a code. In the US we dont, so a delete isnt an issue.

BudVlad · 08-08-2013, 10:58 AM

Quote:

Originally Posted by Rival

if you have an o2 sensor after you will throw a code. In the US we dont, so a delete isnt an issue.

My O2 sensors after secondary cats were installed to Supersprint catless midpipes and I didn’t get any error.

08-07-2013, 09:30 AM	#1
styler Private 12 Rep 65 Posts Drives: E46 M3 & E90 LCI 330i Join Date: Nov 2011 Location: London, UK iTrader: (0)	Secondary cat delete N53 3.0i Hi Guys, I have searched the forum regarding secondary cat delete. Most who have done it say there are oxygen sensors upstream and downstream of the primary cat. I have a oxygen sensor just after the secondary cat also. I want to remove the secondary cats, but i'm not sure if in doing so will throw up emission error. Thanks in advance.
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08-07-2013, 11:34 AM	#2
BudVlad Old Geezer 360 Rep 1,193 Posts Drives: 08 E92 N53B30 Join Date: Jul 2007 Location: Budweis iTrader: (0) Garage List 2008 E92 N53B30 [10.00]	I removed secondary cats by installing Supersprint catless exhaust with O2 sensors. It didn’t throw any error and I passed sniffer test with no problem. __________________
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08-07-2013, 02:27 PM	#3
styler Private 12 Rep 65 Posts Drives: E46 M3 & E90 LCI 330i Join Date: Nov 2011 Location: London, UK iTrader: (0)	Cheers bro. Good to hear. I have custom dual exhaust with no resonator or muffler. Still not loud enough, get a bit of low end boom but not much after 4K revs. Looking to make it scream a bit more.
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08-07-2013, 09:36 PM	#4
SDemetris FSAE Dude 62 Rep 759 Posts Drives: E90 328xi Join Date: Jul 2012 Location: Pittsburgh, PA iTrader: (0)	Got rid of mine with no problem. Just had an exhaust shop weld in some straight piping. But I must have a different setup because i have no O2 sensors after mine __________________ 2007 TiAg 328xi: AA Tune, AFE intake, Full exhaust, 335xi Brakes, H&R RSB, UUC FSB, H&R Sports, Billy Sports...BBS SR 17x8 1985 Gazelle Beige 325e: Poly everything, e24 3.25 LSD, 225 lb weight reduction, Corbeau FX1, Shifter machined by me, roll bar, harness, all the other goodies. My "Racecar"...15x7 BBS RA
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08-08-2013, 04:14 AM	#5
Phil325i Brigadier General 616 Rep 3,194 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	OP be aware that the UK MOT test now requires all factory-fit emissions devices to be in place. So while your car may pass the emissions test, the absence of the cat could be a mandatory fail... __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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08-08-2013, 08:30 AM	#6
Rival Captain 66 Rep 790 Posts Drives: 95 z28 Join Date: Jul 2012 Location: shytown iTrader: (0)	if you have an o2 sensor after you will throw a code. In the US we dont, so a delete isnt an issue. __________________ 2010 335i M sport 2008 328i 2006 325i 1995 Z28 6spd - 377rwhp rip
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