Has anyone ever burned up/clogged their cats before?

vegasspeed · 11-17-2010, 05:01 PM

I have a NSX that is super charged and they reccommend not putting hiflo cats on the car with forced induction because the standalones tend to run rich and clog the cats. Is there any chance that would happen with a 335i with downpipes and hi flow cats? Comments?

also, how often do people here throw a SES light during their ownership?

Jeff@TopGearSolutions · 11-17-2010, 05:09 PM

A fully tuned standalone on any car should not clog cats... sounds like it might be tuned obnoxiously rich in that case.

Anyway I dont hear much about clogging cats around here if ever at all.

This car is direct injection, so it runs leaner then your standard port fuel injection car even with forced induction.

Most port injection cars (forced induction added) run between 11-11.9 Air fuel, where as these cars run as lean as 12.5 seamlessly.

SES lights? What is your real question?

stratplaya06 · 11-17-2010, 11:05 PM

My dad burned up the cats on his e60 m5 at 80k miles, but apparently those cars inherently run rich. Cost for two new headers was 12,000 bucks. BMW did a good will repair, which was awesome. Haven't heard about any issues with n54 powered cars though.

BrianMN · 11-17-2010, 11:15 PM

The only time I've known to burn up cats is by running significant amounts of leaded race gas

Bimmer This · 11-18-2010, 12:13 AM

any car running extremely rich will eventually clog cats. Sounds like your NSX isn't properly tuned. You wouldn't happen to know how much air/fuel ratio it is running woud you?

11-17-2010, 05:01 PM	#1
vegasspeed Captain 84 Rep 761 Posts Drives: 335i 6MT coupe Montego Blue Join Date: Apr 2008 Location: Las Vegas iTrader: (1)	Has anyone ever burned up/clogged their cats before? I have a NSX that is super charged and they reccommend not putting hiflo cats on the car with forced induction because the standalones tend to run rich and clog the cats. Is there any chance that would happen with a 335i with downpipes and hi flow cats? Comments? also, how often do people here throw a SES light during their ownership? __________________ 335i coupe Montego Blue Dinan stage 3 tune, Advan RS wheels 350whp/365wtq 1994 Brooklands Green Acura NSX Comptech Supercharged 390whp/300wtq
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11-17-2010, 05:09 PM	#2
Jeff@TopGearSolutions 3474 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	A fully tuned standalone on any car should not clog cats... sounds like it might be tuned obnoxiously rich in that case. Anyway I dont hear much about clogging cats around here if ever at all. This car is direct injection, so it runs leaner then your standard port fuel injection car even with forced induction. Most port injection cars (forced induction added) run between 11-11.9 Air fuel, where as these cars run as lean as 12.5 seamlessly. SES lights? What is your real question? Last edited by Jeff@TopGearSolutions; 11-17-2010 at 05:14 PM..
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11-17-2010, 11:05 PM	#3
stratplaya06 Captain 47 Rep 967 Posts Drives: 2008 E92 335xi-SOLD 5.0 Miata Join Date: May 2008 Location: Maryland iTrader: (10)	My dad burned up the cats on his e60 m5 at 80k miles, but apparently those cars inherently run rich. Cost for two new headers was 12,000 bucks. BMW did a good will repair, which was awesome. Haven't heard about any issues with n54 powered cars though. __________________ \| PROcede Rev3 \| Vishnu Meth \| DCI \| BMW Perf. Exhaust \| AR Coated/Catless \| CP-E FMIC \| Quaife \|
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11-17-2010, 11:15 PM	#4
BrianMN Banned 117 Rep 2,428 Posts Drives: 4 Door Family Sedan Join Date: Sep 2009 Location: Minneapolis iTrader: (7)	The only time I've known to burn up cats is by running significant amounts of leaded race gas
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11-18-2010, 12:13 AM	#5
Bimmer This Major General 103 Rep 6,473 Posts Drives: 2007 BMW 335i Join Date: Nov 2008 Location: Westminster iTrader: (3)	any car running extremely rich will eventually clog cats. Sounds like your NSX isn't properly tuned. You wouldn't happen to know how much air/fuel ratio it is running woud you?
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