VRSF Catless downpipe w/o a Tune

Richards335 · 03-07-2017, 10:27 PM

So I recently purchased the Remus Sport exhaust and the sound difference between that and the stock is apparently really little. I'm trying to go a little louder, so I'm thinking maybe a catless downpipe.

I have read online and the shop has also told me that its bad to install a downpipe without a tune. Apparently the car would "run rich." So I'm wondering if theres anyone out there who has been running the catless DP on their cars without a tune and have had any problems thus far?

GripAndRip · 03-08-2017, 08:36 AM

Quote:

Originally Posted by Richards335

I have read online and the shop has also told me that its bad to install a downpipe without a tune.

You are going to also have a CEL the entire time. That alone bothers me enough to get a tune lmao

flexbrah · 03-08-2017, 08:53 AM

When I flash back to stock map, I get a CEL within a few minutes of driving. Maybe just get a JB+ for the tiny power boost but gets rid of the CEL (I think)

GripAndRip · 03-08-2017, 12:57 PM

Quote:

Originally Posted by flexbrah

When I flash back to stock map, I get a CEL within a few minutes of driving. Maybe just get a JB+ for the tiny power boost but gets rid of the CEL (I think)

I don't think Jb+ gets rid of CEL. It only adjusts the boost up by tricking the ecu into seeing lower boost. I don't think it clears codes. It says it doesn't require entering ecu area to install either.

BKBMW335I · 03-08-2017, 01:25 PM

Quote:

Originally Posted by flexbrah;21383943[B

]When I flash back to stock map, I get a CEL within a few minutes of driving.[/B] Maybe just get a JB+ for the tiny power boost but gets rid of the CEL (I think)

This +1!! Happens every time but I use my Cobb and clear it and no more CEL.

Just get a tune or some type of reset tool like Autozone has that reads your codes and then can clear the CEL in the meantime.

GATORB8 · 03-08-2017, 01:37 PM

Quote:

Originally Posted by GripAndRip

I don't think Jb+ gets rid of CEL. It only adjusts the boost up by tricking the ecu into seeing lower boost. I don't think it clears codes. It says it doesn't require entering ecu area to install either.

Correct, JB+ only changes the signal at the TMAP sensor in the charge pipe. No interface with ECU or OBD.

GripAndRip · 03-08-2017, 01:38 PM

Quote:

Originally Posted by GATORB8

Quote:

Originally Posted by GripAndRip

I don't think Jb+ gets rid of CEL. It only adjusts the boost up by tricking the ecu into seeing lower boost. I don't think it clears codes. It says it doesn't require entering ecu area to install either.

Correct, JB+ only changes the signal at the TMAP sensor in the charge pipe. No interface with ECU or OBD.

That's what I thought. It just plays middle man and adjusts the reported voltage or information the ecu receives from boost sensor.

On a side note, depending on how much a clear tool is.... you might be better off buying the MHD monitor tool for android. If you have an android, all you need is the cables to connect to obd. It clears and reads codes. It also opens the door for an amazing tuning option when you are ready.

Oh and it allows you to log which is pretty fun and informative.

LGCubana · 03-08-2017, 04:11 PM

If your county/borough requires emissions testing for your inspection sticker, do you have a plan to counter the catless DP ?

Quote:

Originally Posted by Richards335

So I recently purchased the Remus Sport exhaust and the sound difference between that and the stock is apparently really little. I'm trying to go a little louder, so I'm thinking maybe a catless downpipe.

I have read online and the shop has also told me that its bad to install a downpipe without a tune. Apparently the car would "run rich." So I'm wondering if theres anyone out there who has been running the catless DP on their cars without a tune and have had any problems thus far?

WJMSprtXDrive · 03-08-2017, 05:09 PM

You can get solid HP/TQ increase with a Catted DP also and you don't have to worry about any smells. Some tunes will add pops, burbles and extra sounds to even a stock exhaust so keep that in mind.
If you just want the best sounding exhaust take your time and do the research(Youtube, forums etc) and go from there. Don't rush.

mike@x-ph.com · 03-08-2017, 10:39 PM

Quote:

Originally Posted by Richards335

So I recently purchased the Remus Sport exhaust and the sound difference between that and the stock is apparently really little. I'm trying to go a little louder, so I'm thinking maybe a catless downpipe.

I have read online and the shop has also told me that its bad to install a downpipe without a tune. Apparently the car would "run rich." So I'm wondering if theres anyone out there who has been running the catless DP on their cars without a tune and have had any problems thus far?

Congrats on your REMUS exhaust!

Car will run fine without a tune, but you will get a CEL code from the downpipes

aaron_ · 03-09-2017, 05:57 AM

I have a Remus race axle back. Let me say that the sound is ALOT louder than stock with standard dp.

With catless midpipe it sounds like shit. I'm actually changing back to oem dp coz it's aweful

Catless dp without a tune will be rough. It will work but it won't be refined at all. I had my catless dp without a tune for 1 week.

Wait till you install the Remus. If it's too quiet I highly recommend catted dp's

inevitab1e · 03-09-2017, 02:42 PM

What if you have the PPK, JB4 and DP? I'm assuming going to Map 0 on the JB4 will enable the PPK again. But won't this be ill advised due to the DP? CEL lights when back to PPK (map 0)?

AtlasM · 03-09-2017, 03:11 PM

If you want to run a catless downpipe without a tune and avoid CEL you need a downpipe fix. The Area 74 downpipe fix modifies the oxygen sensor signals to make the ECU think there's still a properly functioning cat. VRSF resells it. I have it in my car and when I ran it with PPK flash only (which does not do anything about CEL codes) it successfully prevented CEL codes and the ECU showed full emissions readiness.

The JB4 blocks your car from throwing a CEL from a catless DP by auto-clearing the DP-related codes. But the code is still stored in the ECU.

MHD Stage 2 maps basically ignores the DP codes but does not show cat readiness for emissions purposes.

If you run MHD and the DP fix, you have to flash back to stage 0 and complete multiple drive cycles to get the emissions readiness monitors to reset.

03-07-2017, 10:27 PM	#1
Richards335 Private 22 Rep 93 Posts Drives: 2011 335i Xdrive e92 Join Date: Oct 2015 Location: NYC iTrader: (0)	VRSF Catless downpipe w/o a Tune So I recently purchased the Remus Sport exhaust and the sound difference between that and the stock is apparently really little. I'm trying to go a little louder, so I'm thinking maybe a catless downpipe. I have read online and the shop has also told me that its bad to install a downpipe without a tune. Apparently the car would "run rich." So I'm wondering if theres anyone out there who has been running the catless DP on their cars without a tune and have had any problems thus far?
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03-08-2017, 08:53 AM	#3
flexbrah hehe ty men 32 Rep 172 Posts Drives: 23 M3 Comp xDrive Join Date: Jul 2012 Location: FL iTrader: (1)	When I flash back to stock map, I get a CEL within a few minutes of driving. Maybe just get a JB+ for the tiny power boost but gets rid of the CEL (I think)
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03-08-2017, 05:09 PM	#9
WJMSprtXDrive Private 49 Rep 79 Posts Drives: F15 xDrive50i M-Sport Join Date: Feb 2017 Location: NYC now DC Metro iTrader: (0) Garage List 2011 BMW E90 335i x ... [0.00] 2014 BMW X5 [0.00]	You can get solid HP/TQ increase with a Catted DP also and you don't have to worry about any smells. Some tunes will add pops, burbles and extra sounds to even a stock exhaust so keep that in mind. If you just want the best sounding exhaust take your time and do the research(Youtube, forums etc) and go from there. Don't rush. __________________ 2011 E90 335i xDrive 6AT Performance Edition Package, M-Sport, TTFS Tune, VRSF 3.5" Catted DP, Active Autowerke CP, Turner Motorsport Strut Tower Brace, Hawk HP+, Bilstein B6, Alpina B3 TCU Flash, K&N ---- 2014 F15 X5 xDrive50i M-Sport, RSE, 3rd Row
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03-09-2017, 05:57 AM	#11
aaron_ Captain 90 Rep 671 Posts Drives: E93 335i LCI Join Date: Dec 2015 Location: Sydney iTrader: (0)	I have a Remus race axle back. Let me say that the sound is ALOT louder than stock with standard dp. With catless midpipe it sounds like shit. I'm actually changing back to oem dp coz it's aweful Catless dp without a tune will be rough. It will work but it won't be refined at all. I had my catless dp without a tune for 1 week. Wait till you install the Remus. If it's too quiet I highly recommend catted dp's
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03-09-2017, 02:42 PM	#12
inevitab1e Second Lieutenant 49 Rep 220 Posts Drives: '13 135i N55 FBO Join Date: Feb 2017 Location: there iTrader: (0)	What if you have the PPK, JB4 and DP? I'm assuming going to Map 0 on the JB4 will enable the PPK again. But won't this be ill advised due to the DP? CEL lights when back to PPK (map 0)?
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03-09-2017, 03:11 PM	#13
AtlasM Captain 285 Rep 615 Posts Drives: '11 E92 335xi 6MT Join Date: Jun 2013 Location: Rockville, MD iTrader: (0) Garage List 2011 BMW 335i xDrive [8.00]	If you want to run a catless downpipe without a tune and avoid CEL you need a downpipe fix. The Area 74 downpipe fix modifies the oxygen sensor signals to make the ECU think there's still a properly functioning cat. VRSF resells it. I have it in my car and when I ran it with PPK flash only (which does not do anything about CEL codes) it successfully prevented CEL codes and the ECU showed full emissions readiness. The JB4 blocks your car from throwing a CEL from a catless DP by auto-clearing the DP-related codes. But the code is still stored in the ECU. MHD Stage 2 maps basically ignores the DP codes but does not show cat readiness for emissions purposes. If you run MHD and the DP fix, you have to flash back to stage 0 and complete multiple drive cycles to get the emissions readiness monitors to reset.
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