WTB: N54 OEM Downpipe Cats or DP Fix

TwinTurboRacer · 08-14-2014, 03:36 PM

Looking to go back to the OEM Downpipes. Currently have AR Catless DP on now. Willing to trade + cash as well (local swap out is doable). Here's the thing, I have a 2010 E93 RWD N54 335i. I've read the XI models are different parts. I've also read that the pre/post 08/2009 DP's are different part numbers. Just to be sure, when sending me an offer, send me your year/model and part numbers. I would need it shipped to NJ if you're not relatively local.

OR... If anyone has a DP fix, I'd be interested in that as well.

TwinTurboRacer · 08-18-2014, 11:12 AM

Anyone have anything? And can someone confirm/deny the pre/post 08/2009 part numbers?

TwinTurboRacer · 08-19-2014, 08:54 PM

Bumpity bump...

GODDSPD · 08-19-2014, 10:41 PM

I would consider a trade for my stock DPs but I'm not sure how we would go about doing that. Feel free to PM me with some ideas.

335iNavyGuy · 08-20-2014, 04:02 AM

I have a set of stock ones i can sell you, but they would have to be shipped.

TwinTurboRacer · 08-21-2014, 06:17 PM

I'm assuming both of yours are pre-08/2009 builds based on your signatures? Can you give me your Part numbers off both cats so I can cross reference? From what I've been told by the BMW dealer and confirmed with some part stores online, there's a different part number for pre/post 08/2009 cats. Also, PM me a price. Apologies in advance if I don't answer right away. Will be away on business for a few days. Will try to check in as often as possible.

TwinTurboRacer · 08-29-2014, 05:23 AM

Still looking guys and gals... Anyone?

335iNavyGuy · 08-29-2014, 05:30 AM

Ah sorry you didnt tag me in your reply, so i had no idea you replied, make sure to hit Quote, so the people knnow you are talking to them.

I dont have a part number, but yes mine is pre 08. As long as its an N54 they should fit regardless. I'll take 75 plus shipping. Let me know (seems a pretty fair price for dp's with cats etc)

TwinTurboRacer · 08-29-2014, 02:03 PM

PM'd you about it.

TwinTurboRacer · 09-03-2014, 11:16 PM

Alrightly, I needed to pass inspection so I just ended up making my own dual line DP Fix. Confirmed both O2 sensors have independent signals so it should be safe to leave it in there long term, unlike the commercial ones that share the same signal to the ECU. I have a bunch of extra male/female pinned wires and would be willing to help others make their own, maybe as part of a service swap meet? Would just need to source out more resistors as I tapped out the local Microcenter.

I'm still open to buying an OEM DP from a 2009-2010 model if anyone has one for sale.

Spun Crankhub · 09-14-2014, 12:36 AM

Quote:

Originally Posted by TwinTurboRacer

Alrightly, I needed to pass inspection so I just ended up making my own dual line DP Fix. Confirmed both O2 sensors have independent signals so it should be safe to leave it in there long term, unlike the commercial ones that share the same signal to the ECU. I have a bunch of extra male/female pinned wires and would be willing to help others make their own, maybe as part of a service swap meet? Would just need to source out more resistors as I tapped out the local Microcenter.

I'm still open to buying an OEM DP from a 2009-2010 model if anyone has one for sale.

How did you go about making your own fix?

TwinTurboRacer · 09-16-2014, 12:24 PM

Fix was the same as in the DIY's all over this and other boards. Microcenter was out of 2.2 ohm resistors so I doubled up (in series) 1.1 ohm resistors for each "line" I made. The only difference was to make two lines instead of sharing the single O2 input. This allowed the ECU to read accurate (well modified accurate) readings for each bank. Haven't had any issues so far and IMO would resolve other people's issues with the incorrect fuel trim due to sharing the same signal on both banks on the commercially built ones.

For anyone local to me, I wouldn't mind helping build/solder it up for you, so long as you supplied the parts. Microcenter near me (Paterson) just remodeled so doubt I can find the resistors you need there as I bought everything that was on the shelf. Might be luckier somewhere else, possibly even Radioshack.

Simple diagram:
(Line 19/20) O2 input -> 2.2ohm resistor -> XXX ->ECU input (Line 19/20)
\-->10ohm Resistor -> Ground (Chassis or Line 23)

Line 19/20 would replaced with the new line you make and/or cut and spliced with this setup.
Line 23 would only be T-tapped or you can use a chassis ground.

I didn't take photos before I taped (sealed) and installed mine, but if there's enough demand, I wouldn't mind making one for someone locally (you buy parts) and take photos along the way. Maybe even take a video of the before and after O2 sensor readings as proof of independent signals if someone doesn't believe me?

If anyone needs a new 10ohm variable resistor (potentiometer), I have one of those as well ($10). I was originally going to duplicate the "commercial" designs, but decided to try the dual line method.

08-14-2014, 03:36 PM	#1
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	WTB: N54 OEM Downpipe Cats or DP Fix Looking to go back to the OEM Downpipes. Currently have AR Catless DP on now. Willing to trade + cash as well (local swap out is doable). Here's the thing, I have a 2010 E93 RWD N54 335i. I've read the XI models are different parts. I've also read that the pre/post 08/2009 DP's are different part numbers. Just to be sure, when sending me an offer, send me your year/model and part numbers. I would need it shipped to NJ if you're not relatively local. OR... If anyone has a DP fix, I'd be interested in that as well.
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08-18-2014, 11:12 AM	#2
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	Anyone have anything? And can someone confirm/deny the pre/post 08/2009 part numbers?
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08-19-2014, 08:54 PM	#3
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	Bumpity bump...
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08-19-2014, 10:41 PM	#4
GODDSPD Second Lieutenant 35 Rep 236 Posts Drives: 335i Join Date: Dec 2013 Location: Orange County iTrader: (2)	I would consider a trade for my stock DPs but I'm not sure how we would go about doing that. Feel free to PM me with some ideas.
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08-20-2014, 04:02 AM	#5
335iNavyGuy Colonel 205 Rep 2,349 Posts Drives: 07 N54 E92 Join Date: May 2013 Location: San Diego CA iTrader: (3)	I have a set of stock ones i can sell you, but they would have to be shipped. __________________ 07 E92 Jb4-G5 - Sport Exhaust - Titek BOV BBS Lm reps - AFE dual cone intake
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08-21-2014, 06:17 PM	#6
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	I'm assuming both of yours are pre-08/2009 builds based on your signatures? Can you give me your Part numbers off both cats so I can cross reference? From what I've been told by the BMW dealer and confirmed with some part stores online, there's a different part number for pre/post 08/2009 cats. Also, PM me a price. Apologies in advance if I don't answer right away. Will be away on business for a few days. Will try to check in as often as possible.
	Appreciate 0 Quote

08-29-2014, 05:23 AM	#7
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	Still looking guys and gals... Anyone?
	Appreciate 0 Quote

08-29-2014, 05:30 AM	#8
335iNavyGuy Colonel 205 Rep 2,349 Posts Drives: 07 N54 E92 Join Date: May 2013 Location: San Diego CA iTrader: (3)	Ah sorry you didnt tag me in your reply, so i had no idea you replied, make sure to hit Quote, so the people knnow you are talking to them. I dont have a part number, but yes mine is pre 08. As long as its an N54 they should fit regardless. I'll take 75 plus shipping. Let me know (seems a pretty fair price for dp's with cats etc) __________________ 07 E92 Jb4-G5 - Sport Exhaust - Titek BOV BBS Lm reps - AFE dual cone intake
	Appreciate 0 Quote

08-29-2014, 02:03 PM	#9
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	PM'd you about it.
	Appreciate 0 Quote

09-03-2014, 11:16 PM	#10
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	Alrightly, I needed to pass inspection so I just ended up making my own dual line DP Fix. Confirmed both O2 sensors have independent signals so it should be safe to leave it in there long term, unlike the commercial ones that share the same signal to the ECU. I have a bunch of extra male/female pinned wires and would be willing to help others make their own, maybe as part of a service swap meet? Would just need to source out more resistors as I tapped out the local Microcenter. I'm still open to buying an OEM DP from a 2009-2010 model if anyone has one for sale.
	Appreciate 0 Quote

09-16-2014, 12:24 PM	#12
TwinTurboRacer Private First Class 7 Rep 105 Posts Drives: 2010 E93 335i Join Date: Jul 2014 Location: NJ iTrader: (1)	Fix was the same as in the DIY's all over this and other boards. Microcenter was out of 2.2 ohm resistors so I doubled up (in series) 1.1 ohm resistors for each "line" I made. The only difference was to make two lines instead of sharing the single O2 input. This allowed the ECU to read accurate (well modified accurate) readings for each bank. Haven't had any issues so far and IMO would resolve other people's issues with the incorrect fuel trim due to sharing the same signal on both banks on the commercially built ones. For anyone local to me, I wouldn't mind helping build/solder it up for you, so long as you supplied the parts. Microcenter near me (Paterson) just remodeled so doubt I can find the resistors you need there as I bought everything that was on the shelf. Might be luckier somewhere else, possibly even Radioshack. Simple diagram: (Line 19/20) O2 input -> 2.2ohm resistor -> XXX ->ECU input (Line 19/20) \-->10ohm Resistor -> Ground (Chassis or Line 23) Line 19/20 would replaced with the new line you make and/or cut and spliced with this setup. Line 23 would only be T-tapped or you can use a chassis ground. I didn't take photos before I taped (sealed) and installed mine, but if there's enough demand, I wouldn't mind making one for someone locally (you buy parts) and take photos along the way. Maybe even take a video of the before and after O2 sensor readings as proof of independent signals if someone doesn't believe me? If anyone needs a new 10ohm variable resistor (potentiometer), I have one of those as well ($10). I was originally going to duplicate the "commercial" designs, but decided to try the dual line method.
	Appreciate 0 Quote