Stock Map ECU Flashing - MHD?

[razor7]

Hey all,

Bought a 2008 N54 135i which has changed hands a bunch of times, and been tracked and salvaged. Twice.

Due to a variety of reasons, I believe there was a tune on this car originally which is keeping the catalyst from switching to "ready."

With a new battery, 7,000 miles, and 8 by-the-book drive cycles, still no luck. Every other emissions component is switching to "ready," I've visually inspected it all to be stock including the cats (down pipes *and* mid pipes), there are no O2 sensor spoofers, etc. There's an abundance of power and the exhaust smells... catalyzed. I've owned a car with a clogged cat and one with no cat - this car behaves exactly as it should.

I've just stumbled across MHD which looks like it can reflash the ECU/DME back to BMW OEM Stock - exactly what I want to do, at the very least to rule it out.

Has anyone done this? Any luck with it?

Thanks,
-TC

[icegrill]

No you need to have backed up the original vin ecu.

[ShocknAwe]

Last time I was fiddling with it I remember seeing a "flash back to stock" option where there was an option to select the most recent factory bin for your DME model. So you may need to know IJEOS/etc, but MHD tells you that in a variety of places in the app, so not hard to figure out. If you have your actual original .bin backed up, use that instead.

[Dylanize]

Did you check for a JB4? Might be as simple as removing that to get "ready" status.

[fastdrivingjr]

You can flash a stock generic map. CHECK the box that allows it to read your OEM kats as well. It will tell you when setting up. I couldnt get readiness quick enough before I Threw a code with the generic one they provide so I have mixed feelings with it.

The car will automatically figure out if your ijeos/etc so dont worry about that.

Make sure you save your original flash before doing anything else.. that will take atleast 20-40minutes.

[razor7]

I fixed the problem by using MHD to flash back a stock map. All sensors (including cat, excluding evap) came back in 1 drive cycle, and the next day it was smogged, title transferred, and reg'd.

I did check for a JB4, it was my first hunch even, but there wasn't one installed.

I wasn't able to make a copy of the tune due to it saying the DME was read-only.

It's back to a Stage 1 MHD map now, I was impressed at the change after going back to stock, I didn't know BMW detuned them that much.

-TC

[bmwfast]

Did you check for a JB4? Might be as simple as removing that to get "ready" status.

I'm struggling to get the car ready after replacing the cat-*** downpipes with the stock ones and reflashing it to stock. The JB4 is still in the car but it is by-passed. Could this be the reason why the O2 sensor and Cat are still "incomplete" ?

If you already went through the same path and figured out a way to get readiness, pls let me know. Much thanks

[xQx]

Originally Posted by icegrill

No you need to have backed up the original vin ecu.

Incorrect. You do not need a backup.

MHD will download the latest OEM stock flash matching your ECU and apply it to your car.

[razor7]

Originally Posted by bmwfast

Did you check for a JB4? Might be as simple as removing that to get "ready" status.

I'm struggling to get the car ready after replacing the cat-*** downpipes with the stock ones and reflashing it to stock. The JB4 is still in the car but it is by-passed. Could this be the reason why the O2 sensor and Cat are still "incomplete" ?

If you already went through the same path and figured out a way to get readiness, pls let me know. Much thanks

For me, putting on the MHD flash fixed it. Try using it to reflash back to an OEM map - your JB4 should continue bypassing it if you've set it up correctly.


Yes, MHD will download the latest MAP. I would have liked to have saved the previous one - maybe it was an actual tune from a dyno - but there was no way for me to, it's gone.

-TC