[z3r06r4v1t1]

Hey guys, I’m new to both the forums and the n54 platform. Recently got an 09 335xi with Hexon turbos on e60, tuned by Ken/Wedge with MHD. Absolutely love the car, it’s very quick and always keeps a smile on my face. However, e is putting a major hole in my wallet, so figured I decided to start running 91 daily and save e for the weekend fun. Don’t mind flashing back and forth as needed despite flash times.

Wedge also wrote a 91 tune for the car, the guy I bought it from just hasn’t gotten it to me yet. I figured while I was buying all of my MHD licensing, I would just get the Stage 2+ Pack so I could start running 91 now. But the car HATES it.

She won’t get into boost, rough idle sometimes, just not a happy lady. Granted, I probably need to replace the plugs and coils as it is, along with valve cleaning, but with that said, it was boosting to 23 psi on e and very rarely misfiring. Now it is normal in vacuum but stops at -.1 psi at WOT along with misfires starting. So. I am not entirely sure what the cause is. Thoughts?

Thanks,
Collin.

[eyelobes]

what codes have you pulled? Sounds like a boost leak or dead turbos to me

[relative4]

Originally Posted by eyelobes

what codes have you pulled? Sounds like a boost leak or dead turbos to me

It boosts 23 PSI on E85, and that sounds like dead turbos to you?

Checking codes is correct, though. If no codes, post a log.

[z3r06r4v1t1]

Originally Posted by relative4

It boosts 23 PSI on E85, and that sounds like dead turbos to you?

Checking codes is correct, though. If no codes, post a log.

My thoughts exactly.

Here are the codes. In MHD, as target boost becomes positive, actual boost will not exceed zero.

As for the codes, o2 and lambda codes have always been there, was told by previous owner that it’s not a big deal due to cat-less DPs. If this is incorrect and I need to just replace sensors then so be it. They’re expensive but small price to pay in the end. Other codes did not come up on Wedge’s tune.

[relative4]

Holy crap. Whatever nightmare modifications Wedge has tuned around for E85, you'll need his tune for 91 as well.

I'd get eyes in there and see what the heck is going on hardware-wise. Somebody will need to get in there for some reason at some point, and it would be nice for the mods not to be a surprise.

[z3r06r4v1t1]

Right. I have been through and through the engine bay/underside and its all pretty solid. Slight boost leak so I plan on starting there. If that doesn’t help, moving to TMAP sensor, them lpfp sensor (thinking a bad sensor could mess with fuel trims and AFRs), from there to new o2 sensors. This is on top of plugs, coils, and valve cleaning. I want the car to be in good shape and run the way it should. Wedge can work some serious magic, but I want it to work with OTS tunes to show me everything is working well. Then will have him write me a new 91 tune to make more power or better efficiency.

Will keep you updated, thanks for the input.

[dpaul]

Originally Posted by z3r06r4v1t1

My thoughts exactly.


As for the codes, o2 and lambda codes have always been there, was told by previous owner that it’s not a big deal due to cat-less DPs..

That's complete nonsense. You have codes for pre-cat sensors - that should never happen.

That said, it's not surprising that the an MHD off-the-shelf tune would not work well at all with your hexon turbo-equipped engine.

To being with, did you try re-flashing the E85 tune?

[z3r06r4v1t1]

Haven’t re-flashed e tune as still have a full tank of 91.

[z3r06r4v1t1]

Well I resolved the problem. Lots of researching and brainstorming lately. Decided just to go through all MHD settings/options again. Didn’t have the box checked for 3.5 bar MAP sensor. Imagine it was throwing off voltage readings and car didn’t know what to do so kept out of boost for safety. Hitting 17 pounds on the 91 tune now. No misfires whatsoever.

Only codes left are these. Planning on resolving boost leak related to the 30ff.

My lambda values are slightly different (2-3). Does this mean there is an exhaust leak which is causing o2 sensor code or is the o2 sensor what needs to be replaced and is therefore causing lambda values to be off?

[dpaul]

Just saying "lambdas are slightly different" isn't enough for anyone to help you.

Clear the codes, reset lambda adaptations, make a log and post it on datazap.

What makes you think you have a boost leak? Just seeing 30FF tells you nothing about why you're not hitting boost targets. Anyway, if you have a boost leak, and can find it, fix it right now before anything else.

[z3r06r4v1t1]

After resetting lambda adaptations, all o2 related codes seem to have gone away. Ran for about 15 minutes, so haven’t gone through a full cycle. Will update in a few days if they return or the confirm the problem to be solved. Lambda values are looking consistent and where they should be. Only code left (currently showing) is the 30FF error.

The reasoning behind assuming the boost leak is previous owner telling me it’s ever so slightly leaking boost somewhere. I have no evidence to back it up but will make a boost tester soon to see.