[ferocity02]

Does this apply to N55 also? I'm noticing a similar behavior usually at the start of a steady cruise anywhere from 50-70mph.

[titan.n54]

Originally Posted by Wolf 335

These oscillations have nothing to do with tunes.

I am stock and have had them. It just dissapeared one day.

How it dissapear?

[titan.n54]

Originally Posted by CarAbuser

It's 100% unrelated to flashing. This is just superstitious nonsense.

All the data im the binary file is checksum protected so if the contents of the flash don't match what was in the data exchange file then the car would not start.

Writing back to stock then writing the OTS maps repeatedly isn't fixing anything. The cause of the oscillations are because of the catalyst and O2 sensor diagnostic routines. I have given the fixes for these problems to Wedge so I expect this will be fixed in the OTS maps in the next revision.

This problem has been discussed in depth on other N54 forums and anyone running a custom tune is able to fix this themselves.

Looks like MHD doesn't apply the fix yet

It would be great to running stock map (Stage 0) without oscillation

[TSilver335i]

Originally Posted by rsalazart

Looks like MHD doesn't apply the fix yet

It would be great to running stock map (Stage 0) without oscillation

Was fixed in version 3.00

- Fixed throttle / lambda oscillation for all flashes when "aftermarket DP" is selected.

I take it your on stock DP's though?

[Wolf 335]

Originally Posted by rsalazart

How it dissapear?

No idea, it just stopped doing it.

[mj6234]

I would say I also noticed my logs the WDGC hitting the floor value, particularly with slow gradual uphills followed by downhills. Since it wanted to go below the floor to reduce load by pulling WDGC, I also got the oscillations. It was plain to see in the logs, and they were more severe than the ones fixed by what carabuser found.

I do have aftermarket twins, but this behavior appeared 10s of thousands of miles after installing them. I am certain that lowering this to 9% from 12.8% helped in my case. I may be somewhat unique, but another thing that contributed.

For me, I had them at highway speeds, in 6th gear, 2900-3000 rpm (80-82mph). Once they appeared, they would happen even at cruising speed at that RPM. Downshifting to 5th would immediately get rid of the behavior.

[Spyro235]

Wow- What a revelation! I had theses issues with my first N54, I'm hoping they don't surface in my current one. I al;ways knew it was 02 related, but didnt know about diagnostic tests running being the cause. I logged and logged and watched my fuel trims bounce, while the throttle position stayed steady, it was so annoying for months.

[titan.n54]

Originally Posted by TSilver335i

Was fixed in version 3.00

- Fixed throttle / lambda oscillation for all flashes when "aftermarket DP" is selected.

I take it your on stock DP's though?

Still oscillating in Stage 0. I'm running v3.05

[Dave92N54]

Fun fact, you won't pass emissions in any state with the new update now. It stops the O2 monitors from readying now as well.

[darkrom]

Originally Posted by Dave92N54

Fun fact, you won't pass emissions in any state with the new update now. It stops the O2 monitors from readying now as well.

Are you sure? I don't see anyone else talking about this. I need to pass emissions next year so I want to stay on this

[Dave92N54]

Originally Posted by darkrom

Are you sure? I don't see anyone else talking about this. I need to pass emissions next year so I want to stay on this

Yes i'm positive. Go get in your car now and check your codes, you'll see Catalyst and the O2 monitors will read "Incomplete".

I confirmed it with my tuner as well. He said currently he doesn't have a work around for it but will let me know.

[darkrom]

Originally Posted by Dave92N54

Yes i'm positive. Go get in your car now and check your codes, you'll see Catalyst and the O2 monitors will read "Incomplete".

I confirmed it with my tuner as well. He said currently he doesn't have a work around for it but will let me know.

Have you messaged MHD about this? They are very responsive I found.

[Dave92N54]

Originally Posted by darkrom

Have you messaged MHD about this? They are very responsive I found.

No, I don't see any reason in it. I'm sure they know about this. I don't think their is anything they can do.

They fixed the oscillations by presumably following the method detailed by CarAbuser. So now some of the diagnostic routines are disabled, therefore the O2 monitor will not ready. Exactly the same as before where the catalyst wouldn't complete because they disabled it.

[CarAbuser]

There may be a workaround in future for getting rid of oscillating afr without preventing o2 sensor readiness but for now you can just flash your tune with stock cat option and those missing monitors will set.

I haven't really looked into it much since for anyone that I tune I just force all monitors to ready so it's not a problem.

[darkrom]

Originally Posted by CarAbuser

There may be a workaround in future for getting rid of oscillating afr without preventing o2 sensor readiness but for now you can just flash your tune with stock cat option and those missing monitors will set.

I haven't really looked into it much since for anyone that I tune I just force all monitors to ready so it's not a problem.

How can you force the monitors to ready I'm asking. If you can force a catless car to say ready, that's amazing and you should show MHD or I wouldn't understand why that's not an OTS option. Not doubting you just surprised no one else is doing that that I've seen. That sounds like it would help everyone pass in some difficult states.

[CarAbuser]

Originally Posted by darkrom

How can you force the monitors to ready I'm asking. If you can force a catless car to say ready, that's amazing and you should show MHD or I wouldn't understand why that's not an OTS option. Not doubting you just surprised no one else is doing that that I've seen. That sounds like it would help everyone pass in some difficult states.

Yes force anything to ready.

MHD can do it but they would fall foul of the local regulations.

[darkrom]

Originally Posted by CarAbuser

Yes force anything to ready.

MHD can do it but they would fall foul of the local regulations.

How is it done, I'll try it with tuner pro and the backend flash maps since I have a jb4 still.

[dmckmc]

In Missouri, the State emission computers can read when catalyst and O2 sensors are tuned out (not supported) even with full monitor readiness. Car failed immediately. See actual pic of state paperwork attached, this was my inspection. DP fix was easiest solve for me. Indeed the car oscillated badly with the stock DP box checked but it was short lived to pass inspection.

[CarAbuser]

Yes, you can't just remove it from the readiness check, it has to be forced into a ready state. This is not done using MHD or any other software that only flashes the calibration segment.

Forcing in the tune is much easier than fitting a DP fix, no drive cycle required.

[theobjectivist]

Originally Posted by CarAbuser

Yes, you can't just remove it from the readiness check, it has to be forced into a ready state. This is not done using MHD or any other software that only flashes the calibration segment.

Forcing in the tune is much easier than fitting a DP fix, no drive cycle required.

So im clear:

Its possible for your tuner to provide a file that will show completely ready?

No hardware changes, no O2 emulators? You simply load the tune and bingo-bongo?

[CarAbuser]

Originally Posted by theobjectivist

So im clear:

Its possible for your tuner to provide a file that will show completely ready?

No hardware changes, no O2 emulators? You simply load the tune and bingo-bongo?

Yes, but I'm the only person that currently offers it. Any tuner that offers it as a service will be a reseller.

[Tangent]

I would love for this to finally actually be fixed but am past holding my breath; it's been annoying me since whatever maps were current in 2017. My engine is completely stock except for the charge pipe and the Stage 1 tune, and I selected the right downpipe option for MHD to not clear codes as proven by passing my smog check a couple of years ago with the tune in place. The surge is there on the Stage 1, 1+ and 0 maps. The only time I've had it go away is after flashing back to stock to pass my most recent smog since they now check for tunes. I left it that way for a few months and enjoyed the smooth cruising but flashed back to Stage 1 a couple of months ago. The surge came right back.