[josephtaye]

Have a 2011 335 FBO on stage 2+ MHD, been having a CEL that comes and goes for almost 2 years, took it to the shop many many times and everything was checked and repaired (valve cover, inlets, outlets, intake, MAF, smoke down test, break booster) and the CEL will be gone for a month or so but now it’s back and stronger then ever, no other codes, no loss of power no rough idle. Could this be something related to the tune? Or a DME or software issue? I need to pass inspection and because of this im stuck! I really need help to pass inspection Cause Apprently there is no boost leak or unmeasured air. I know i can’t be the only one to deal with this, any help is appreciated thank you

[nsjames]

check engine light means codes.

get them in MHD.

[josephtaye]

Originally Posted by nsjames

check engine light means codes.

get them in MHD.

Just getting the system to lean code, for almost 2 years, no other codes at all, it comes and goes, i just need it gone for inspection

[nsjames]

so that can be fuel system or anything related to the o2 sensor feedback, not just a manifold leak.

what do the fuel trims say?
Checked the live o2 sensor voltages?
cats or no?
If no, how was the rear o2 sensor handled?

[josephtaye]

Originally Posted by nsjames

so that can be fuel system or anything related to the o2 sensor feedback, not just a manifold leak.

what do the fuel trims say?
Checked the live o2 sensor voltages?
cats or no?
If no, how was the rear o2 sensor handled?

The O2 sensors, are disabled due to the tune, and the fuel trims are within normal limits according to my shop, catless downpipe. Just out of curiosity and knowledge fuel trims effect a system lean issue?

[nsjames]

disabled how? Too my knowledge MHD will turn off the light, but won't turn off the emissions monitoring for catalyst.

If someone's done the ole DP fix to the rear o2 sensors that may very well be your problem. the rears are used to calibrate the fronts.

[whyzee125]

I think the front o2’s report fuel ratios and the rears report cat efficiency and calibrate the front o2’s. If your rears are truly disabled, they shouldn’t be. Stage 2 and up tunes should keep your light off but all they do is prevent the readiness from setting. It’s likely o2 related or possibly injector related. I would find a new shop that can smoke test your whole intake system and check for leaks. This shouldn’t be tune related but try switching back to stock tune.

[josephtaye]

Originally Posted by nsjames

disabled how? Too my knowledge MHD will turn off the light, but won't turn off the emissions monitoring for catalyst.

If someone's done the ole DP fix to the rear o2 sensors that may very well be your problem. the rears are used to calibrate the fronts.

Just with MHD I might have read the information wrong through MHD disables them. And no DP fix have been used, the only code is system to lean nothing about O2 sensors unless that’s tied into it 🤔

[josephtaye]

Originally Posted by whyzee125

I think the front o2’s report fuel ratios and the rears report cat efficiency and calibrate the front o2’s. If your rears are truly disabled, they shouldn’t be. Stage 2 and up tunes should keep your light off but all they do is prevent the readiness from setting. It’s likely o2 related or possibly injector related. I would find a new shop that can smoke test your whole intake system and check for leaks. This shouldn’t be tune related but try switching back to stock tune.

I would go to another shop if I can find a better one this one I go to is upon one of the best in NY and NJ so it’s even that much concerning after smoke tests and many diagnoses they still have trouble themselves, go back to stock tune with no DP fix?

[nsjames]

Originally Posted by josephtaye

Just with MHD I might have read the information wrong through MHD disables them. And no DP fix have been used, the only code is system to lean nothing about O2 sensors unless that’s tied into it 🤔

MHD turns off the light for the readiness monitor.
it does not "turn them off"
and it won't let you pass emissions testing for the catalyst.


I'd suggest you talk to any of the notable tuners in the n54 scene, wedge, aa, somebody, and send them logs of it and ask them.

[Serf27]

I don’t think you’ll pass without the DP fix.


Last time I had a lean code, I replaced the injector o rings and “crush” washers on them.
Have you done that?