e90 325i (06) --> e90 335i (2010) CAT CONVERTER

shoopdawoop · 03-07-2018, 08:30 PM

anyone know if it's possible to use the cat converters on this 325 for the 335i?

RocketSurgeon · 03-08-2018, 03:44 AM

I'm not sure I understand the question. The n54 exhaust components are only compatible with the n54, you can't use them on other vehicles. The fitment is very different because of the turbos.
If you want to cut the rear cat out of one exhaust and weld it into another, maybe it would work.
What exactly are you trying to do?

JuniorB · 03-08-2018, 06:47 AM

The 325 has a smaller diameter pipe, causing a bottleneck, may also cause backpressure.

shoopdawoop · 03-08-2018, 01:28 PM

Quote:

Originally Posted by RocketSurgeon

I'm not sure I understand the question. The n54 exhaust components are only compatible with the n54, you can't use them on other vehicles. The fitment is very different because of the turbos.
If you want to cut the rear cat out of one exhaust and weld it into another, maybe it would work.
What exactly are you trying to do?

both my 335i cats are out. I have a 325i (same model) that I was going to donate anyway. I need to sell the 335i since the cost of oem cats are nearly as much as the car's worth at this point.

basically want the cheapest legal option repair for the 335i

feuer · 03-08-2018, 02:09 PM

Buy used catalyst converters.

RocketSurgeon · 03-08-2018, 03:20 PM

Did you just recently get the 335i? Is it possible that you have downpipe? How many miles are on the car?
A cat failure is pretty uncommon, especially both at the same time. Considering how many 335s have been crashed, there should be used parts available on the cheap.

techwhiz · 03-08-2018, 05:41 PM

Quote:

Originally Posted by shoopdawoop

anyone know if it's possible to use the cat converters on this 325 for the 335i?

No.

The federal emissions warranty on cats is 8yr/80K miles.
Take it to the dealer.
Cats are different than the standard 7yr/70K high cost item.

Also if you burned them up in under 80K miles your car most definitely has another issue you should be looking at.

I have seen those cats go more than 180K miles with no issues.

dsjr2006 · 03-09-2018, 12:55 PM

Your OE downpipes cats are out? There are tons of them for sale from people that upgraded to catless downpipes. I think I even have a pair laying around I don't want/need.

JuniorB · 03-14-2018, 04:45 PM

I'm going to hope he's talking about the downstream cats and not the upstream. Even tho they look the same, there different in diameter, if your running stock upstream, just run test pipes in the down stream.

03-07-2018, 08:30 PM	#1
shoopdawoop Private First Class 10 Rep 146 Posts Drives: E90 LCI Jet Black 335i Join Date: Jan 2012 Location: Berkeley iTrader: (0)	e90 325i (06) --> e90 335i (2010) CAT CONVERTER anyone know if it's possible to use the cat converters on this 325 for the 335i?
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03-08-2018, 03:44 AM	#2
RocketSurgeon Lieutenant 264 Rep 459 Posts Drives: 2008 135i Manual, CBR650F Join Date: Jan 2017 Location: NC iTrader: (0)	I'm not sure I understand the question. The n54 exhaust components are only compatible with the n54, you can't use them on other vehicles. The fitment is very different because of the turbos. If you want to cut the rear cat out of one exhaust and weld it into another, maybe it would work. What exactly are you trying to do?
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03-08-2018, 06:47 AM	#3
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	The 325 has a smaller diameter pipe, causing a bottleneck, may also cause backpressure.
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03-08-2018, 02:09 PM	#5
feuer Major General 4277 Rep 9,209 Posts Drives: wife crazy! Join Date: Apr 2015 Location: Chicago, IL iTrader: (5)	Buy used catalyst converters.
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03-08-2018, 03:20 PM	#6
RocketSurgeon Lieutenant 264 Rep 459 Posts Drives: 2008 135i Manual, CBR650F Join Date: Jan 2017 Location: NC iTrader: (0)	Did you just recently get the 335i? Is it possible that you have downpipe? How many miles are on the car? A cat failure is pretty uncommon, especially both at the same time. Considering how many 335s have been crashed, there should be used parts available on the cheap.
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03-09-2018, 12:55 PM	#8
dsjr2006 Captain 157 Rep 848 Posts Drives: '01 E39 540iA, '09 E90 M3 Join Date: May 2013 Location: Metro Detroit iTrader: (1) Garage List 2010 BMW 335i [0.00] 2001 BMW 540i [0.00]	Your OE downpipes cats are out? There are tons of them for sale from people that upgraded to catless downpipes. I think I even have a pair laying around I don't want/need. __________________ E90 M3 DCT LCI \| E90 LCI N54 M-Sport(retired) \| E90 Technical Docs download: http://j.mp/bmwe90docs *good read, very detailed.
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03-14-2018, 04:45 PM	#9
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	I'm going to hope he's talking about the downstream cats and not the upstream. Even tho they look the same, there different in diameter, if your running stock upstream, just run test pipes in the down stream.
	Appreciate 0 Quote