[335boston]

Hello all ! I've been having issues with my o2 sensors with my FBO n54 . I've had these codes ever since doing the JB4 and don't have any idea how to fix them or what they are actually showing . I've looked on many forums threads but they all come to the conclusion of a bad o2 sensor and I've now changed all 4 o2 sensors with oem Bosch and they are still here . I do have Catless downpipes , please let me know what you guys think! Thanks in advanced !

[Volasko]

Try unplugging & plugging in the MAF sensor. This cleans the contact surface which may help your situation. I constantly get these CAT errors every half year until I repeat my previous steps. After doing it it takes about 5/6 starts to self clear.

[335boston]

Originally Posted by Volasko

Try unplugging & plugging in the MAF sensor. This cleans the contact surface which may help your situation. I constantly get these CAT errors every half year until I repeat my previous steps. After doing it it takes about 5/6 starts to self clear.

Is the MAP sensor that's in the charge pipe the same as the MAF sensor ? Lol came from an e46 and I thought the n54 didn't have a MAF . Also I am catless don't no if that makes a difference .Thank you for the reply !

[relative4]

Originally Posted by 335boston

Is the MAP sensor that's in the charge pipe the same as the MAF sensor ? Lol came from an e46 and I thought the n54 didn't have a MAF . Also I am catless don't no if that makes a difference .Thank you for the reply !

The N54 does not have a MAF sensor. And yes, being catless makes a difference.

[dpaul]

Do you have a backend flash installed, one with the cat monitors disabled?

If your JB4 software version relatively new and you live in the US, the JB4 will not enable autoclear for cat-related codes. This is a recent change made to reduce their legal liability. So you'll get a CEL with active codes related to the cats because you've removed the converters. The codes you report are not the most typical set of codes that come up but I think this is still a plausible explanation. Backend flash will eliminate this problem but you'll have to edit the file(s) provided by BMS as they do not distribute flashes with monitors disabled.

[335boston]

Originally Posted by dpaul

Do you have a backend flash installed, one with the cat monitors disabled?

If your JB4 software version relatively new and you live in the US, the JB4 will not enable autoclear for cat-related codes. This is a recent change made to reduce their legal liability. So you'll get a CEL with active codes related to the cats because you've removed the converters. The codes you report are not the most typical set of codes that come up but I think this is still a plausible explanation. Backend flash will eliminate this problem but you'll have to edit the file(s) provided by BMS as they do not distribute flashes with monitors disabled.

Hey thanks for the reply , I do indeed have the newest back end flash installed on my car from bms and I used MHD app to install the BEF. These codes have been on the car prior to installing the BEF don't no if that helps . Thanks again!

[dpaul]

You’ll need to edit the BEF to disable cat monitors.

Edit: mhd May be able to do this when you flash the BEF

[dpaul]

Here are instructions on how to edit your BEF. They start at about 4:00 in this video:

[335boston]

Hey, thank you for the link, it seems I should def do this especially since my inspection is coming up, I was wondering if there is anyway to do this with my tablet, I used MHD on my tablet to upload the BEF. I cant seem to find a way to actually open the tune file and edit those parameters on my tablet. Thanks !

Edit: So I ended up just trying to do the process and i got everything set up through TunerPro and I opened the parameters for bank 1 and bank 2 cats the values are already set to 56 so now im very confused. On occasion my codes do come up as "Catless Downpipes detected" so im not sure what to do or what this means lol. Also I forgot to add on occasion, I will be thrown into map 4 safty map, it only happens when I climb the RPMS on part throttle to about 3500-4k rpms and then mass the throttle. Let me know if this helps with the codes. Also since my parameters are set to 56 does this mean ill pass inspection with my catless down pipes lol? Thank you !

[dpaul]

Set them to 0; 56 is the stock (enabled) value

The obd2 flag for cat efficiency will not set if the monitor is disabled. Therefor the inspection station will read it as “not ready” or "incomplete" rather than “fail”. In MA you will pass inspection with one “not ready “ flag.

[335boston]

Originally Posted by dpaul

Set them to 0; 56 is the stock (enabled) value

The obd2 flag for cat efficiency will not set if the monitor is disabled. Therefor the inspection station will read it as "not ready" or "incomplete" rather than "fail". In MA you will pass inspection with one "not ready " flag.

Oh I see thank you ! Got confused because the guy in the video set them to "56" from "0".

[335boston]

Update : having new problems related to o2 sensors , car is now throwing " 2c2b" (lamda probe in front of catalytic converter, system check) error with a rough idle and a stutter on very light throttle. I checked the JB4 when the rough idle was happening and bank 1 afr was at 18 . I shut the car off turned the car on and idle went down to 15.2 I then cleared the codes and I will check tomrrow if it came back . Any ideas on this ? Contacted bms they said there's a error in the 02 sensors somewhere (lol). Anyone have any idea on this? Thanks !

[Aceway]

Try resetting your adaptations

[335boston]

Hey guys wanna give another update . Symptoms are still persisting intermittently, afr spikes lean on bank 1 than will be rich on bank 2 after a while it will level out and return to normal without any symptoms , while this occurs car is stumbling on part throttle and idle is rough , but now I am getting more codes ! I'll attach another picture let me know if you guys have any ideas !


Edit : I also think the first 2 codes are from Catless downpipes like previously discussed , but the rest I think are some sort of error with the car not sure what's happening since all the o2s are new .

[N54Romeo]

[335boston]

Originally Posted by N54Romeo

???

[335boston]

Bump!

[335boston]

Ganna bump this thread with a update and more info to see if anyone can help! I have since taken off the BEF and now running only JB4 . I am getting only 2 o2 sensor codes now I will attach the picture with the list of codes . Please let me know if anyone has any insight . I did have the DP fix in the car for a while and took it out so I may go into the ecu and see if the wires are in the right place lmk if anyone has any idea ! Thank you !

[x800pro6]

Originally Posted by 335boston

Hey guys wanna give another update . Symptoms are still persisting intermittently, afr spikes lean on bank 1 than will be rich on bank 2 after a while it will level out and return to normal without any symptoms , while this occurs car is stumbling on part throttle and idle is rough , but now I am getting more codes ! I'll attach another picture let me know if you guys have any ideas !


Edit : I also think the first 2 codes are from Catless downpipes like previously discussed , but the rest I think are some sort of error with the car not sure what's happening since all the o2s are new .

I'm having the exact same problem identical!! It's wrecking my brains. I changed bank 1 o2 sensor and still have same error on bank 1 identical to you. Eventually your correct the AFR balances out

[SingleTurbskie]

Originally Posted by x800pro6

I'm having the exact same problem identical!! It's wrecking my brains. I changed bank 1 o2 sensor and still have same error on bank 1 identical to you. Eventually your correct the AFR balances out

Did you guys figure it out yet? I’m single turbo and already switch plugs, coils and o2’s and still throwing o2s codes