car runs fine stock, jb4 makes it run haywire. anyone in houston have a cobb/pro/etc?

phrenetiK · 04-30-2012, 08:09 PM

bought a used 135i with full bolt ons and a jb4. dp, midpipe, axleback, and dual cone intake. car is SLOWER THAN STOCK with all these mods. didn't find this rut until i raced and drove a stock 135i.

getting some lambda codes, i replaced o2 sensors, and spark plugs. nothing helped. then i had the idea to take off the jb4.

boom instantly the car was running great. no more rough idle, boosted correctly, pulled hard and instant torque. that led me to believe the jb4 was screwed up. then we installed the jb4 on my friends stock 135i. it turned his car into a MONSTER. my car should even pull harder than it does with all my supporting mods, however that was not the case. we put the jb4 back on my car and same thing. starts idling rough, only boosts to 3psi 1st 5 psi 2nd, 9 psi 3rd...so slow. also throws more lambda codes. take off the jb4 again and bam instantly making over stock performance.

i have no idea whats wrong but would like to testsomething like a cobb or procede on the car and see if they both cause the car to run shitty too, or if my car strangely just hates the jb4?

im running out of ideas here and have been at this for 2 weeks now and nothing i try is working.

tl;dr car is faster without jb4 on any map(1,2,5). same jb4 turns friends car into a beast. wtf?

anyone local have something we can test besides a jb4 for an afternoon?

BMW86 · 04-30-2012, 08:12 PM

What are the codes?

cooler2442 · 04-30-2012, 08:13 PM

Something is obviously wrong with your car then if you put the JB4 on someone's car and it made his car a monster. You will just be making it worse by putting a Cobb on it that may conceal your problem until something really bad happens.

I would buy the USB cable and take some log's then email that to Terry so he can diagnose it for you.

phrenetiK · 04-30-2012, 08:15 PM

2C7F Lambda probe behind catalytic converter 2, trimm control
> 2C6A No Description Found
> 2C31 Lambda probe in front of catalytic converter, trimming control
> 2C32 Lambda probe in front of catalytic converter 2, trimming control

per terrys instructions i spent 400 replacing o2 sensors and the codes for upstream o2 sensors are still there after installing the new ones.

the o2 sensor plugin by the bumper is plugged into the downpipe closest to the bumper, and the exhaust side plugin is plugged into the downpipe closest to the exhaust. that is correct i imagine?

i have done several logs and he has not said a word about them. my afrs are dangerously low and my ecu boost is usually stupid low.

BMW86 · 04-30-2012, 08:19 PM

My car was in the shop last week to make adjustments to the exhaust and it's been throwing similar codes since then too, going back into the shop to sort it out. I think the o2 sensors were removed and then put back in the wrong way around. Unfortunately, I don't know which way is the right way though. Weird thing is they said they didn't touch the sensors but I didn't actually speak to the person that worked on my car so I'm not 100% certain. I'll check my codes and see if they're the same. They keep reappearing.

lucaa135 · 05-01-2012, 04:39 PM

check your car to make sure that when you take the JB4 on and off all of the little teeth on the connectors are standing up and making good connections, if they aren't then you could be having some of these misfires. I put my jb4 on backwards once and it ruined my car, i couldn't even get it to start. An hour later i took it off and back on (did it right) and the car goes beast. You should also update your software

Lambobimmer · 05-01-2012, 04:54 PM

I believe that your O2's are not hooked up correctly.

stevenc · 05-01-2012, 07:13 PM

Im in Houston and veyr experienced with JB4 is you want me to take a look.

Mike@N54Tuning.com · 05-01-2012, 09:01 PM

If you are getting lambda codes either the JB4 is defective, is installed wrong, or you have some actual lambda issue like a misfired or damaged o2 sensor, or a misadjusted DPFIX, etc. The best thing to do is to clear all codes and remove the JB4, and run around stock for a few weeks. If the car runs perfectly during that time with no lambda codes then the JB4 or harness must be defective.

Mike

luv135i · 05-01-2012, 10:46 PM

Quote:

Originally Posted by Mike@N54Tuning.com

If you are getting lambda codes either the JB4 is defective, is installed wrong, or you have some actual lambda issue like a misfired or damaged o2 sensor, or a misadjusted DPFIX, etc. The best thing to do is to clear all codes and remove the JB4, and run around stock for a few weeks. If the car runs perfectly during that time with no lambda codes then the JB4 or harness must be defective.

Mike

Wouldnt the jb4 running flawlessly on his friends car rule out the jb4 and harness being defective?

:

BMW86 · 05-01-2012, 11:36 PM

Quote:

Originally Posted by Mike@N54Tuning.com

If you are getting lambda codes either the JB4 is defective, is installed wrong, or you have some actual lambda issue like a misfired or damaged o2 sensor, or a misadjusted DPFIX, etc. The best thing to do is to clear all codes and remove the JB4, and run around stock for a few weeks. If the car runs perfectly during that time with no lambda codes then the JB4 or harness must be defective.

Mike

Mike, you've got me worried now. My shop had to work on my downpipes recently and I've been throwing similar codes since then, it's been about 2 weeks now. Car seems to run normal but haven't been able to push it hard either. I hope they didn't damage my o2 sensors in the process. Haven't touched the JB4.

JefryHorizon · 05-01-2012, 11:38 PM

check all your mods to see if they were put on correctly since you've crossed out the fact that your JB4 unit isn't running. Did the previous owner do all the installs himself? Going to his usual shop might get you some answers as well.

phrenetiK · 05-02-2012, 10:02 AM

my only guess could be the o2 sensors being in backwards or something?

they are brand new wideband sensors and i put them in the same spot they were in before, but maybe that was wrong?

like i said the connector closer to the front of the engine bay is plugged into the downpipe closest to the front bumper. and the rear connector to the rear downpipe. anyone know off the top of your head if that is right/wrong?

pnosker · 05-02-2012, 11:03 AM

Do you guys not have auto code clear on? If not, turn it on... you'll get codes if you have DPs with it not enabled.

Also, if your rear O2 sensors are installed in the front or if banks 1-3 are in the 4-6 port, you'll have the same sort of issues.

phrenetiK · 05-02-2012, 11:07 AM

no i turned off auto code clear so i can diagnose the problems with the car.

Tommeh · 05-02-2012, 11:28 AM

I have similar issues with my 135i. I am on average pulling 3-5 pounds of boost and it throws a CEL engine code when I WOT my car. I have had this issue for a year now and can't figure out the problem. I drove to MFEST and at one point was able to max out the car and in 6th gear in high RPMs the boost only got to 8 pounds but that was at speeds of 160+ and a lot of RPM climbing.

Interested in your fix, I think im going to take out my JB4 as clearly I am not reaching the 12-18 limit I should be obtaining and am not pulling stock boost anyway. Im going to try to get it to BMW Austin at some point and get to the bottom of this issue.

BFD99 · 05-02-2012, 11:38 AM

Wonder if you can send your JB4 into terry for inspection, just to rule that out? Then I'd go back and start looking at O2 sensors like you already mentioned. I don't know what else it could be!?? Good luck man.

Mike@N54Tuning.com · 05-02-2012, 02:26 PM

Quote:

Originally Posted by Tommeh

I have similar issues with my 135i. I am on average pulling 3-5 pounds of boost and it throws a CEL engine code when I WOT my car. I have had this issue for a year now and can't figure out the problem. I drove to MFEST and at one point was able to max out the car and in 6th gear in high RPMs the boost only got to 8 pounds but that was at speeds of 160+ and a lot of RPM climbing.

Interested in your fix, I think im going to take out my JB4 as clearly I am not reaching the 12-18 limit I should be obtaining and am not pulling stock boost anyway. Im going to try to get it to BMW Austin at some point and get to the bottom of this issue.

Read the codes and email them with a csv log to bms. Sounds like a boost leak or you have the in dash boost gauge set wrong.

Mike

phrenetiK · 05-02-2012, 03:48 PM

sounds like tommeh has the exact same problem as me.

hopefully one of us figures it out and can help the other!

you car should go back to 7-8 psi and normal power after taking off your jb4 as well. let me know if thats the case, then we know we're both experiencing the same thing.

04-30-2012, 08:09 PM	#1
phrenetiK Banned 36 Rep 357 Posts Drives: 08 135i Join Date: Mar 2012 Location: Houston, TX iTrader: (4)	car runs fine stock, jb4 makes it run haywire. anyone in houston have a cobb/pro/etc? bought a used 135i with full bolt ons and a jb4. dp, midpipe, axleback, and dual cone intake. car is SLOWER THAN STOCK with all these mods. didn't find this rut until i raced and drove a stock 135i. getting some lambda codes, i replaced o2 sensors, and spark plugs. nothing helped. then i had the idea to take off the jb4. boom instantly the car was running great. no more rough idle, boosted correctly, pulled hard and instant torque. that led me to believe the jb4 was screwed up. then we installed the jb4 on my friends stock 135i. it turned his car into a MONSTER. my car should even pull harder than it does with all my supporting mods, however that was not the case. we put the jb4 back on my car and same thing. starts idling rough, only boosts to 3psi 1st 5 psi 2nd, 9 psi 3rd...so slow. also throws more lambda codes. take off the jb4 again and bam instantly making over stock performance. i have no idea whats wrong but would like to testsomething like a cobb or procede on the car and see if they both cause the car to run shitty too, or if my car strangely just hates the jb4? im running out of ideas here and have been at this for 2 weeks now and nothing i try is working. tl;dr car is faster without jb4 on any map(1,2,5). same jb4 turns friends car into a beast. wtf? anyone local have something we can test besides a jb4 for an afternoon?
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04-30-2012, 08:12 PM	#2
BMW86 Major General 398 Rep 9,156 Posts Drives: RS3 Sedan / Macan S Join Date: Jul 2008 Location: Australia iTrader: (0)	What are the codes?
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04-30-2012, 08:13 PM	#3
cooler2442 Brigadier General 477 Rep 4,154 Posts Drives: 1/18 Monte Carlo Blue E92 M3 Join Date: Apr 2011 Location: Los Angeles iTrader: (6) Garage List 2016 Porsche GT4 [0.00]	Something is obviously wrong with your car then if you put the JB4 on someone's car and it made his car a monster. You will just be making it worse by putting a Cobb on it that may conceal your problem until something really bad happens. I would buy the USB cable and take some log's then email that to Terry so he can diagnose it for you.
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04-30-2012, 08:15 PM	#4
phrenetiK Banned 36 Rep 357 Posts Drives: 08 135i Join Date: Mar 2012 Location: Houston, TX iTrader: (4)	2C7F Lambda probe behind catalytic converter 2, trimm control > 2C6A No Description Found > 2C31 Lambda probe in front of catalytic converter, trimming control > 2C32 Lambda probe in front of catalytic converter 2, trimming control per terrys instructions i spent 400 replacing o2 sensors and the codes for upstream o2 sensors are still there after installing the new ones. the o2 sensor plugin by the bumper is plugged into the downpipe closest to the bumper, and the exhaust side plugin is plugged into the downpipe closest to the exhaust. that is correct i imagine? i have done several logs and he has not said a word about them. my afrs are dangerously low and my ecu boost is usually stupid low.
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04-30-2012, 08:19 PM	#5
BMW86 Major General 398 Rep 9,156 Posts Drives: RS3 Sedan / Macan S Join Date: Jul 2008 Location: Australia iTrader: (0)	My car was in the shop last week to make adjustments to the exhaust and it's been throwing similar codes since then too, going back into the shop to sort it out. I think the o2 sensors were removed and then put back in the wrong way around. Unfortunately, I don't know which way is the right way though. Weird thing is they said they didn't touch the sensors but I didn't actually speak to the person that worked on my car so I'm not 100% certain. I'll check my codes and see if they're the same. They keep reappearing.
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05-01-2012, 04:39 PM	#6
lucaa135 Private 6 Rep 88 Posts Drives: 2009 135i Join Date: Jul 2011 Location: West Coast iTrader: (1)	check your car to make sure that when you take the JB4 on and off all of the little teeth on the connectors are standing up and making good connections, if they aren't then you could be having some of these misfires. I put my jb4 on backwards once and it ruined my car, i couldn't even get it to start. An hour later i took it off and back on (did it right) and the car goes beast. You should also update your software __________________ Space Grey 135i: BMS DCI, JB4, AA Downpipes, Berk Full Street Exhaust.
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05-01-2012, 04:54 PM	#7
Lambobimmer Major 292 Rep 1,473 Posts Drives: 2022 X3 M40i, 2018 TTRS Join Date: Jan 2010 Location: Tarheel iTrader: (14)	I believe that your O2's are not hooked up correctly. Last edited by Lambobimmer; 05-01-2012 at 04:59 PM..
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05-01-2012, 07:13 PM	#8
stevenc Coming Soon 254 Rep 960 Posts Drives: 2015 BMW M4 Alphine White MT Join Date: Apr 2008 Location: Houston, TX iTrader: (0)	Im in Houston and veyr experienced with JB4 is you want me to take a look.
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05-01-2012, 09:01 PM	#9
Mike@N54Tuning.com Joint Chiefs of Staff 4912 Rep 115,980 Posts Drives: 2007 335i, 2015 M3 Join Date: Dec 2008 Location: N54tuning.com iTrader: (89)	If you are getting lambda codes either the JB4 is defective, is installed wrong, or you have some actual lambda issue like a misfired or damaged o2 sensor, or a misadjusted DPFIX, etc. The best thing to do is to clear all codes and remove the JB4, and run around stock for a few weeks. If the car runs perfectly during that time with no lambda codes then the JB4 or harness must be defective. Mike
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05-01-2012, 11:38 PM	#12
JefryHorizon Lieutenant 12 Rep 437 Posts Drives: Bus Pass Join Date: Sep 2011 Location: Ktown iTrader: (3)	check all your mods to see if they were put on correctly since you've crossed out the fact that your JB4 unit isn't running. Did the previous owner do all the installs himself? Going to his usual shop might get you some answers as well. __________________ E30 x2 Sold E39 x2 Sold E46 x3 Sold E82 x1 Sold E60 x1 Furniture...
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05-02-2012, 10:02 AM	#13
phrenetiK Banned 36 Rep 357 Posts Drives: 08 135i Join Date: Mar 2012 Location: Houston, TX iTrader: (4)	my only guess could be the o2 sensors being in backwards or something? they are brand new wideband sensors and i put them in the same spot they were in before, but maybe that was wrong? like i said the connector closer to the front of the engine bay is plugged into the downpipe closest to the front bumper. and the rear connector to the rear downpipe. anyone know off the top of your head if that is right/wrong?
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05-02-2012, 11:03 AM	#14
pnosker ti fan 67 Rep 273 Posts Drives: 14 12C \| 17 X5 50i \| 19 M2C Join Date: Jan 2008 Location: NJ iTrader: (1) Garage List 2014 McLaren 12C Sp ... [0.00] 2017 BMW X5 xDrive50i [0.00] 2019 BMW M2 Competi ... [0.00] 2008 BMW 535xi Touring [10.00] 2008 BMW 135i [10.00]	Do you guys not have auto code clear on? If not, turn it on... you'll get codes if you have DPs with it not enabled. Also, if your rear O2 sensors are installed in the front or if banks 1-3 are in the 4-6 port, you'll have the same sort of issues.
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05-02-2012, 11:07 AM	#15
phrenetiK Banned 36 Rep 357 Posts Drives: 08 135i Join Date: Mar 2012 Location: Houston, TX iTrader: (4)	no i turned off auto code clear so i can diagnose the problems with the car.
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05-02-2012, 11:28 AM	#16
Tommeh Lieutenant 56 Rep 481 Posts Drives: 96 BMW M3 & 16 GMC Canyon Join Date: Mar 2011 Location: Washington iTrader: (0)	I have similar issues with my 135i. I am on average pulling 3-5 pounds of boost and it throws a CEL engine code when I WOT my car. I have had this issue for a year now and can't figure out the problem. I drove to MFEST and at one point was able to max out the car and in 6th gear in high RPMs the boost only got to 8 pounds but that was at speeds of 160+ and a lot of RPM climbing. Interested in your fix, I think im going to take out my JB4 as clearly I am not reaching the 12-18 limit I should be obtaining and am not pulling stock boost anyway. Im going to try to get it to BMW Austin at some point and get to the bottom of this issue.
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05-02-2012, 11:38 AM	#17
BFD99 The Stig! 54 Rep 889 Posts Drives: 2008 135i 6MT Join Date: Sep 2011 Location: Tulsa, Ok iTrader: (1) Garage List 2008 BMW 135i [10.00]	Wonder if you can send your JB4 into terry for inspection, just to rule that out? Then I'd go back and start looking at O2 sensors like you already mentioned. I don't know what else it could be!?? Good luck man. __________________ 2008 135i - FBO + JB4 15ohm + Water Meth
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05-02-2012, 03:48 PM	#19
phrenetiK Banned 36 Rep 357 Posts Drives: 08 135i Join Date: Mar 2012 Location: Houston, TX iTrader: (4)	sounds like tommeh has the exact same problem as me. hopefully one of us figures it out and can help the other! you car should go back to 7-8 psi and normal power after taking off your jb4 as well. let me know if thats the case, then we know we're both experiencing the same thing.
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