Factory Downpipe?

VXEric · 10-06-2018, 10:55 AM

Hi all, my 335 has had an intermittent CEL for a few months now that goes away after long highway trips and stays off as long as i baby the car. if i drive it hard, it usually comes on after a few miles, always when i let off the throttle.

With the JB4 it gives me about 10 different codes. all are "unknown" and haven't found any searching here or the N54Tech forum.

With ISTA I get codes mostly related to the O2 Sensor (after cat) and slow response, occasionally high resistance and rarely a code for the pre-cat sensor. Usually a code related to coasting.

I figured it was a clogged downpipe because the PO ran the car on MAP2 and he said he had only replaced the mufflers, midpipes are stock and i thought the downpipe was stock. I have been running MAP1, and the light still comes on occasionally with JB4 on MAP0 too.

I got a VSRF catted DP and started working to replace but found what looks like a catless DP fix on one of the oxygen sensor leads. Its pretty beat up looking.

Is this a factory downpipe? Any ideas what could be throwing all of these codes? Thanks in advance!

From the top
https://drive.google.com/file/d/1PZL...ew?usp=sharing

From underneath
https://drive.google.com/file/d/1de9...ew?usp=sharing

Connection to midpipe
https://drive.google.com/file/d/1cdr...ew?usp=sharing

Codes
https://drive.google.com/file/d/1RP_...ew?usp=sharing

VXEric · 10-06-2018, 11:13 AM

Heres what I assume is a catless DP fix.

https://drive.google.com/file/d/1_ni...ew?usp=sharing

rich_mane · 10-06-2018, 04:25 PM

Kind of looks like an OEM downpipe, but they have studs at the midpipe connection, not nuts and bolts. Not sure what kind it is.

I'd be more concerned about that active Valvetronic deactivation fault more than the O2 faults personally. Does that one consistently come back?

VXEric · 10-06-2018, 04:36 PM

Yes that's always there but doesn't trigger a CEL.

maddmatth · 10-06-2018, 05:01 PM

Quote:

Originally Posted by VXEric

Yes that's always there but doesn't trigger a CEL.

That is a problem though. Your valvetronic system is faulty.
And there's the blocked blow off valve.

The codes are post cat so either that sensor, or the cat is blocked or breaking up.

Also... you seem to have an N54, but you posted in the N55 section. N55 doesn't have a blow off valve. The two midpipe connections also give that way, N55 only has one.
Edit: Whoops I'm wrong about the midpipe, my bad.

VXEric · 10-06-2018, 05:34 PM

I appreciate the feedback, not sure what the valvetronic system not functioning does to the car. I'll have to read up on it some more. I did pull both vanos solenoids out and soaked them in carb cleaner to no avail.

It's definitely an N55. 2011, single turbo, one downpipe. Every photo I've seen of an N55 downpipe has two mid pipes and one downpipe. N54 has two downpipe.

I'm wondering if it could be a DME issue too. I guess tomorrow I'll pull the downpipe and see what kind of condition is in. The JB4 gives me a totally different set of codes than ISTA. If I get a BOV code without a BOV, that would point to a computer problem.

Anyone know how the DP fix actually works? I assumed the issue couldn't be the post cat sensor because there's a dp fix tied into the wiring for it, that should mask a faulty sensor anyway. Or does it just adjust one specific output?

maddmatth · 10-06-2018, 06:09 PM

Oh yeah you're right, sorry... the blow off valve code is strange though. Maybe it's referring to the diverter valve?

rich_mane · 10-06-2018, 07:05 PM

The blow off valve code is known as a common tuner code... I had it when running the BMS Stage 1 and everything pointed to just being a tuner code. My diverter valve seemed to be functioning normally.

The valvetronic is essentially the throttle control for the N55... It's a pretty important piece to performance. The valvetronic motor probably failed, valve cover has to come off to replace it. I feel like that would definitely cause a CEL once you try to floor it and the valves don't open up as much as they are supposed to..

VXEric · 10-07-2018, 08:45 AM

Well, confirmed that the DP is aftermarket and that it is not a clogging issue.

Anyone in the market for a brand new catted VRSF downpipe?

Next step is to remove the DP fix and see if the codes change.

weehe126 · 10-07-2018, 09:34 AM

DP looks like a catted AR design maybe? None of the aftermarket catted DP kept the CEL off 100% of the time so would explain it. As said above the valvetronic code probably means the motor died and you are now using the throttle body instead, so that is why it still drives.

10-06-2018, 10:55 AM	#1
VXEric Private 28 Rep 62 Posts Drives: 2011 E90 335xi 6MT Join Date: Nov 2015 Location: Philadelphia, PA iTrader: (1)	Factory Downpipe? Hi all, my 335 has had an intermittent CEL for a few months now that goes away after long highway trips and stays off as long as i baby the car. if i drive it hard, it usually comes on after a few miles, always when i let off the throttle. With the JB4 it gives me about 10 different codes. all are "unknown" and haven't found any searching here or the N54Tech forum. With ISTA I get codes mostly related to the O2 Sensor (after cat) and slow response, occasionally high resistance and rarely a code for the pre-cat sensor. Usually a code related to coasting. I figured it was a clogged downpipe because the PO ran the car on MAP2 and he said he had only replaced the mufflers, midpipes are stock and i thought the downpipe was stock. I have been running MAP1, and the light still comes on occasionally with JB4 on MAP0 too. I got a VSRF catted DP and started working to replace but found what looks like a catless DP fix on one of the oxygen sensor leads. Its pretty beat up looking. Is this a factory downpipe? Any ideas what could be throwing all of these codes? Thanks in advance! From the top https://drive.google.com/file/d/1PZL...ew?usp=sharing From underneath https://drive.google.com/file/d/1de9...ew?usp=sharing Connection to midpipe https://drive.google.com/file/d/1cdr...ew?usp=sharing Codes https://drive.google.com/file/d/1RP_...ew?usp=sharing Last edited by VXEric; 10-06-2018 at 11:09 AM.. Reason: fix mispelled title
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10-06-2018, 11:13 AM	#2
VXEric Private 28 Rep 62 Posts Drives: 2011 E90 335xi 6MT Join Date: Nov 2015 Location: Philadelphia, PA iTrader: (1)	Heres what I assume is a catless DP fix. https://drive.google.com/file/d/1_ni...ew?usp=sharing
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10-06-2018, 04:25 PM	#3
rich_mane First Lieutenant 139 Rep 227 Posts Drives: 2011 E92 335i Join Date: Jan 2016 Location: S.FL iTrader: (1)	Kind of looks like an OEM downpipe, but they have studs at the midpipe connection, not nuts and bolts. Not sure what kind it is. I'd be more concerned about that active Valvetronic deactivation fault more than the O2 faults personally. Does that one consistently come back?
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10-06-2018, 04:36 PM	#4
VXEric Private 28 Rep 62 Posts Drives: 2011 E90 335xi 6MT Join Date: Nov 2015 Location: Philadelphia, PA iTrader: (1)	Yes that's always there but doesn't trigger a CEL.
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10-06-2018, 05:34 PM	#6
VXEric Private 28 Rep 62 Posts Drives: 2011 E90 335xi 6MT Join Date: Nov 2015 Location: Philadelphia, PA iTrader: (1)	I appreciate the feedback, not sure what the valvetronic system not functioning does to the car. I'll have to read up on it some more. I did pull both vanos solenoids out and soaked them in carb cleaner to no avail. It's definitely an N55. 2011, single turbo, one downpipe. Every photo I've seen of an N55 downpipe has two mid pipes and one downpipe. N54 has two downpipe. I'm wondering if it could be a DME issue too. I guess tomorrow I'll pull the downpipe and see what kind of condition is in. The JB4 gives me a totally different set of codes than ISTA. If I get a BOV code without a BOV, that would point to a computer problem. Anyone know how the DP fix actually works? I assumed the issue couldn't be the post cat sensor because there's a dp fix tied into the wiring for it, that should mask a faulty sensor anyway. Or does it just adjust one specific output?
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10-06-2018, 06:09 PM	#7
maddmatth Major 555 Rep 922 Posts Drives: F82 M4, E92 335i Join Date: Jun 2015 Location: New Zealand iTrader: (0)	Oh yeah you're right, sorry... the blow off valve code is strange though. Maybe it's referring to the diverter valve?
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10-06-2018, 07:05 PM	#8
rich_mane First Lieutenant 139 Rep 227 Posts Drives: 2011 E92 335i Join Date: Jan 2016 Location: S.FL iTrader: (1)	The blow off valve code is known as a common tuner code... I had it when running the BMS Stage 1 and everything pointed to just being a tuner code. My diverter valve seemed to be functioning normally. The valvetronic is essentially the throttle control for the N55... It's a pretty important piece to performance. The valvetronic motor probably failed, valve cover has to come off to replace it. I feel like that would definitely cause a CEL once you try to floor it and the valves don't open up as much as they are supposed to..
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10-07-2018, 08:45 AM	#9
VXEric Private 28 Rep 62 Posts Drives: 2011 E90 335xi 6MT Join Date: Nov 2015 Location: Philadelphia, PA iTrader: (1)	Well, confirmed that the DP is aftermarket and that it is not a clogging issue. Anyone in the market for a brand new catted VRSF downpipe? Next step is to remove the DP fix and see if the codes change.
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10-07-2018, 09:34 AM	#10
weehe126 Brigadier General 1161 Rep 3,185 Posts Drives: 2017 340i Join Date: Apr 2014 Location: San Antonio iTrader: (2)	DP looks like a catted AR design maybe? None of the aftermarket catted DP kept the CEL off 100% of the time so would explain it. As said above the valvetronic code probably means the motor died and you are now using the throttle body instead, so that is why it still drives.
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