AFR difference between the banks

Mitco39 · 07-04-2014, 10:05 PM

Quote:

Originally Posted by Jordo!

Hmm. So that doesn't affect the detection logic, it just turns off the CEL... that's probably randomly screwing with things for a lot of folks

Having the two O2's on one bank sounds like it very well might be the problem! Actually, if they are located on the same downpipe, one after the other rather than on separate but parallel paths, they are probably reading latency in voltage change from the primaries quite differently, and that could result in wonky corrections being applied.

One more thought if it isn't the O2's: Are you using bigger injectors? The k multiplier (I can't recall if that scales for size, injector latency or both) might need to be tweaked if it was left at stock values.

Jordo, thats how it is in a bunch of other ECUs I've played with. I would expect this one to be no different. I have not tested out that fact but I would be very surprised if this one did something other than the Bosche/Delphi ECUs I have played with.

The double O2's could most definitely be the issue and right now thats the next thing I am going to do (been a bit busy as of late so I haven't played with the car at all as of yet.

I do have larger injectors and the K multiplier was changed accordingly. Even if that wasn't dialed in properly you would just see that in the correction factors as well as at WOT you would go lean or rich depending on how far out your K factor is. Essentially any of those changes will absolutely affect the AFRs but under closed loop the computer will do its best to account for any errors in the tune itself and if your to far out you will get lean or rich bank codes.

Tomorrow I am installing CJMs fuel return system which will warrant a full redo of the fuel tables so I will be playing with UpRev alot then. As I type this I am soldering together my own device for listening to the knock sensor with headphones that they have posted on their website.

Mitco39 · 07-08-2014, 12:18 PM

To anyone following this thread unplugging the O2s fixed the trim issue. The car is now doing a much better job at meeting its targets. Haven't had extensive time on it yet, but it does seem to be much better.

roplusbee · 07-09-2014, 12:35 AM

That makes me sad. How am I supposed to pass emissions testing if I have to disable my O2 sensors to get the car to not flip out?

gendr777 · 10-15-2014, 01:34 AM

Not sure if this issue is still circulating about the forum. I was having the same issue. Bank 1 and bank 2 were always off by 0.5-0.7. An accidental wipe of my rom file lead me to this series of adjustments which virtually eliminated the disparity.

1) I downloaded a different rom from uprev by accident. I flashed the 2013 370 NISMO file 1A40D instead of the one my ecu was supposed to match:1A39D.

2) I began running all uprev programs as administrator.

3) I edged up my injector latency value at 14V a bit (added 0.3ms).

That's it. Like the majority of useful medications on the market, this was a serendipitous discovery. I hope this helps at least one other person.

Peace.
-JMC

Jordo! · 10-15-2014, 02:48 AM

Quote:

Originally Posted by Mitco39

To anyone following this thread unplugging the O2s fixed the trim issue. The car is now doing a much better job at meeting its targets. Haven't had extensive time on it yet, but it does seem to be much better.

unplugged the secondary or the primary -- I'm guessing the former?

Mitco39 · 10-15-2014, 09:39 AM

Quote:

Originally Posted by gendr777

Not sure if this issue is still circulating about the forum. I was having the same issue. Bank 1 and bank 2 were always off by 0.5-0.7. An accidental wipe of my rom file lead me to this series of adjustments which virtually eliminated the disparity.

1) I downloaded a different rom from uprev by accident. I flashed the 2013 370 NISMO file 1A40D instead of the one my ecu was supposed to match:1A39D.

2) I began running all uprev programs as administrator.

3) I edged up my injector latency value at 14V a bit (added 0.3ms).

That's it. Like the majority of useful medications on the market, this was a serendipitous discovery. I hope this helps at least one other person.

Peace.
-JMC

Your point 3 might be the reason you're not seeing this happen anymore. Are both your secondary O2s on the same bank?

Quote:

Originally Posted by Jordo!

unplugged the secondary or the primary -- I'm guessing the former?

Secondary, they been unplugged all summer with 0 issues.

jwick · 10-15-2014, 10:01 AM

Quote:

Originally Posted by Mitco39

Your point 3 might be the reason you're not seeing this happen anymore. Are both your secondary O2s on the same bank?

Secondary, they been unplugged all summer with 0 issues.

This is on my todo list for the V1.75 upgrade. Bought the plugs to be able to pull them completely!

Mitco39 · 10-15-2014, 10:27 AM

Quote:

Originally Posted by jwick

This is on my todo list for the V1.75 upgrade. Bought the plugs to be able to pull them completely!

yeah.... i been lazy...

flashgordon · 11-05-2016, 12:25 PM

Reading this thread I am looking also in my engine a little differences between banks: 0.5-0.8 AFR, but only in 1800-3600RPM Full Load area!

In this case, it's better to tune all richer maintaining all Bank1 & Bank2 MAX AFR below 12.7, or I must consider a mid value?

...after 4000RPM everything the AFR was balanced...

Some positive feedbacks removing the O2s?

Thanks.

flashgordon · 11-06-2016, 03:13 PM

Quote:

Originally Posted by flashgordon

Reading this thread I am looking also in my engine a little differences between banks: 0.5-0.8 AFR, but only in 1800-3600RPM Full Load area!

In this case, it's better to tune all richer maintaining all Bank1 & Bank2 MAX AFR below 12.7, or I must consider a mid value?

...after 4000RPM everything the AFR was balanced...

Some positive feedbacks removing the O2s?

Thanks.

The two banks are pretty close, but in the 3250RPM area, there is a difference

Two examples:

ihiryu · 11-09-2016, 11:56 AM

flashgordon · 11-09-2016, 02:10 PM

Quote:

Originally Posted by ihiryu

....mmh! I know....

My question is:

If you have an AFR balanced on the entire range, but only around 1800-3600RPM Bank1 differs from bank2....

What do you do? ....disconnecting O2s (The lambda after the cats) is the solution?

ihiryu · 11-09-2016, 06:54 PM

Hmm that is strange.

Here's a silly question, but is your MAF voltages during that area? Wonder if it's possible that the MAF's are reading slightly different from one another?

flashgordon · 11-10-2016, 06:19 AM

Quote:

Originally Posted by ihiryu

Hmm that is strange.

Here's a silly question, but is your MAF voltages during that area? Wonder if it's possible that the MAF's are reading slightly different from one another?

Interesting!

....this weekend I can try to swap the 2 sensors....

ihiryu · 11-10-2016, 12:32 PM

Try it and report if the AFR dip changes between the banks.

I would also double check to make sure you don't have any vacuum/air leaks post MAF. I would imagine a vacuum leak on a MAF based system could make things run funny.

07-08-2014, 12:18 PM	#32 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	To anyone following this thread unplugging the O2s fixed the trim issue. The car is now doing a much better job at meeting its targets. Haven't had extensive time on it yet, but it does seem to be much better. __________________ 2007 Chevy Duramax - EFILive Tuned By Me 2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her My Build --> http://www.the370z.com/members-370z-...39s-build.html

07-09-2014, 12:35 AM	#33 (permalink)
roplusbee A True Z Fanatic Join Date: Dec 2009 Location: Killeen, TX Posts: 2,360 Drives: 2007 350Z NISMO Rep Power: 23	That makes me sad. How am I supposed to pass emissions testing if I have to disable my O2 sensors to get the car to not flip out? __________________ 2007 350Z NISMO #0618: Zerolift \| UPREV \| F.I. \| Greddy \| Competition Clutch \| Injector Dynamics \| Aeromotive \| Pioneer \| JL

10-15-2014, 01:34 AM	#34 (permalink)
gendr777 Base Member Join Date: Jul 2013 Location: Texas Posts: 8 Drives: 13 Nissan 370Z BK M6 Rep Power: 12	Serendepity solved this one for me. Not sure if this issue is still circulating about the forum. I was having the same issue. Bank 1 and bank 2 were always off by 0.5-0.7. An accidental wipe of my rom file lead me to this series of adjustments which virtually eliminated the disparity. 1) I downloaded a different rom from uprev by accident. I flashed the 2013 370 NISMO file 1A40D instead of the one my ecu was supposed to match:1A39D. 2) I began running all uprev programs as administrator. 3) I edged up my injector latency value at 14V a bit (added 0.3ms). That's it. Like the majority of useful medications on the market, this was a serendipitous discovery. I hope this helps at least one other person. Peace. -JMC

11-05-2016, 12:25 PM	#39 (permalink)
flashgordon Premium Member Join Date: Sep 2009 Location: Italy Posts: 146 Drives: 370z Rep Power: 16	Reading this thread I am looking also in my engine a little differences between banks: 0.5-0.8 AFR, but only in 1800-3600RPM Full Load area! In this case, it's better to tune all richer maintaining all Bank1 & Bank2 MAX AFR below 12.7, or I must consider a mid value? ...after 4000RPM everything the AFR was balanced... Some positive feedbacks removing the O2s? Thanks. __________________ HFC Berk - CAI Stillen GEN3 - Catback Nismo - ECU reflash with UpRev - Clutch South Bend Stage II daily with ZSpeed HD CSC - Setrab Oil Cooler Kit with Mishimoto Thermostatic Plate Gold - PJMu Brake Pads - Oil Pressure Gauge GlowShift - TPMs Hella TC400 - Steering Lock disable switch by me - OBD Link MX with Asus Nexus & Torque App

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
AFR's off between banks HELP!	12nismo	Engine & Drivetrain	10	09-18-2013 09:50 PM
FI TDX Gen 1 and Gen 2 Difference	7sinz	Intake/Exhaust	6	05-12-2013 11:10 PM
BBQ Spanish Banks Sunday July 22nd	Sena	Canada	76	07-25-2012 12:16 AM
Difference between PG and GM?	Noc	Exterior & Interior	5	04-15-2011 06:25 PM
Difference between 09 and 10	SkyZ	Nissan 370Z General Discussions	32	03-27-2010 01:03 PM

11-09-2016, 11:56 AM	#41 (permalink)
ihiryu Base Member Join Date: Oct 2016 Location: TX Posts: 141 Drives: 2013 Nismo 370z 6MT Rep Power: 34

11-09-2016, 06:54 PM	#43 (permalink)
ihiryu Base Member Join Date: Oct 2016 Location: TX Posts: 141 Drives: 2013 Nismo 370z 6MT Rep Power: 34	Hmm that is strange. Here's a silly question, but is your MAF voltages during that area? Wonder if it's possible that the MAF's are reading slightly different from one another?

11-10-2016, 12:32 PM	#45 (permalink)
ihiryu Base Member Join Date: Oct 2016 Location: TX Posts: 141 Drives: 2013 Nismo 370z 6MT Rep Power: 34	Try it and report if the AFR dip changes between the banks. I would also double check to make sure you don't have any vacuum/air leaks post MAF. I would imagine a vacuum leak on a MAF based system could make things run funny.