[2BitRoach]

Interesting...no need to flash back with stage 1

[LuxoM3]

Resurrecting this thread as I have to smog by 435i up here in NorCal.
I've got the BootMod3 DME.
So the verdict is still the following?

1. Charge the car overnight
2. Unlock and reflash the DME back to stock
3. Lock the DME
4. Drive for last least 100 miles.
5. Get it smogged?

Thanks gents!

[ErikB]

This is a useful thread, thanks. I will have to do this next year on my 2018 and I had emailed PTF about locking and unlocking the DME and they never really answered my question. Glad some of you here were able to lock for smog and unlock again after just using the bm3 app.

[d2un21]

FYI - I was able to pass without flashing back to stock (stage 1. no dp). I forgot about my tune when I went in. This was back in July.

The spot I went to didn't do a visual check either so I'm guessing if I put on the DP I have sitting around, it might've passed. However, I'm not sure if the test that's done has some range for emissions values and whether a high flow catted DP would still cause that to fail (tuned or not).

[LuxoM3]

OK gonna resurrect this thread as it's coming up for more and more of us as the 8 years has expired!

My car info:

- 2015 BMW 435i, stage 1 BM3
- 80k miles
- Minor engine mods like VRSF charge pipe and intercooler
- MPPK airbox

Been running the BM3 for 1 year.
Reflashed back to stock AND re-locked the DME about month ago,
then put about 500 miles on the car since then.

Went in today for SMOG in Norcal with a local shop.
I was mentally prepared for the tailpipe stick, ODB plug in, underhood inspection.

NOPE.

Talked to the SMOG tech, learned a few things...
1. No dyno/roller test on newer cars (like last 10 years)
2. No tail pipe sniffer test, but will gas it for a visual smoke test - excess black or white smoke is a fail.
3. Yes, ODB plug-in scan... which looks for these things (see Torque App screen, which you can do yourself to "pre-test")

4. Yes, he does pop the hood and look for stuff. So if it ain't black and stock looking, it won't fly. The VRSF charge pipe is black, metal.
5. Yes, he will walk the car with a under-body mirror - looking for non-stock headers or missing cats.
6. Battery - he said if you got a new battery, drive the car for at least a hundred miles. He's seen cars with new batteries fail because the emission checks haven't cleared or readied themselves.

I was in/out in 5 minutes for the test.
Heck 15 if you count the small talk.
So in short, with the F3X cars, it's more about the equipment working and telling the OBD2 system, yep were are good. Not so much about actual emissions.

I used the torque app to pre-check mine a couple weeks ago.
This is the actual list the SMOG guy looks at on screen and my results...

VISUAL:
Air Inspection Sysem - NA
Computers, Sensors, Switching, Wiring - Pass
Exhaust Gas Recirculation (EGR) - NA
Fuel Metering System - Pass
Turbo/Supercharger - NA
Catalyst - Pass
Crankcase Emission Controls - Pass
Fuel Evaporative System (EVAP) - Pass
Other Emission Related - Pass
Vaccuum Lines to Sensors - Pass

My take on this, just make sure nothing looks disconnected or touched. This REALLY needs to look like it was bought off a lot and dirty from a few years of driving.

[B]EMISSION CONTROL:[\B]
Liquid Fuel Leak Check - Pass
Smoke Check - Pass
OBD2 - Pass


Hope this helps some of you guys.
I've been through SMOG fails before with my 95 M3 (dead cats).
This was a cake walk.

[SpoolinAddict]

Has anyone ever tried getting a smog with Fabspeed Catted Downpipe and stock tune and locked DME? Is it possible to pass? or do you have to find someone to pass you for visual?

[LuxoM3]

Well theoretically...
1. If there are no markings or shiny chrome or any visual way to give away that you aren't stock.
2. If the DME is locked
3. If there's no smoke out the tailpipe
4. If they don't do a tail-pipe sensor

Then you *could* pass because all the checks are software, smoke, and visual...

[4coupe440i]

Originally Posted by McGyv3r

Yes. Someone on here flashed back to stock, but didn't lock the DME. They failed and were sent to a referee.

It's not a thing about being thorough, its about math and it's automatic. The checksum is just adding up all the 1's and 0's in the DME's code. Compare that value to a known good value. If your checksum is off, you fail. Any changes to the factory tune will change your value, so you fail.

I am from Europe and I reckon in the near future we will get the same checks to see if the DME was flashed.

So this makes me wonder... I totally understand how they can easily verify a known checksum and determine from there if the software was tampered with. But... where do 'they' get the checksum from? Is BMW supplying them with a very long list of checksums for every possible engine & car variation?

Does anybody have more insight on that?

[NEWTRON]

Originally Posted by 4coupe440i

I am from Europe and I reckon in the near future we will get the same checks to see if the DME was flashed.

So this makes me wonder... I totally understand how they can easily verify a known checksum and determine from there if the software was tampered with. But... where do 'they' get the checksum from? Is BMW supplying them with a very long list of checksums for every possible engine & car variation?

Does anybody have more insight on that?

Yes, BMW supplied a list. I assume its the same list the dealer uses to determine ecu tamper for warranty claims.

[halcyon_waves]

Originally Posted by SpoolinAddict

Has anyone ever tried getting a smog with Fabspeed Catted Downpipe and stock tune and locked DME? Is it possible to pass? or do you have to find someone to pass you for visual?

I'm looking into this exact downpipe for this exact reason lol. Based on what I've heard from others, this will pass visual and smog. But curious to see what others who have first hand experience have to say. The price is rather steep and I'd hate to have issues when I have to re-smog in a couple years.

[SpoolinAddict]

Originally Posted by halcyon_waves

I'm looking into this exact downpipe for this exact reason lol. Based on what I've heard from others, this will pass visual and smog. But curious to see what others who have first hand experience have to say. The price is rather steep and I'd hate to have issues when I have to re-smog in a couple years.

Yeah it's a pain in the ass but I'm just worried the readiness monitors won't be fully ready with that downpipe. It's a expensive part to just gamble on since catted and catless dp are only 300-400

[BushF30]

Hello, I just did my smog last month and I passed . I just put the stock down pipe back and flashed stock tune . Also I didn’t have to lock the dme. I did do the drive cycle and drove 300 miles. Also just checked if all the emissions status was completed

[wesmeister]

My wagon just passed first-ever smog check. I kept putting it off and ran into needing to register my car asap, so I never flashed back. Passed no problem with Stage 1 flash and stock cat.

[F18 Hornet]

Originally Posted by BushF30

Hello, I just did my smog last month and I passed . I just put the stock down pipe back and flashed stock tune . Also I didn’t have to lock the dme. I did do the drive cycle and drove 300 miles. Also just checked if all the emissions status was completed

Hello. Sorry to resurrect a dead thread but you had no problem smogging without locking the DME? For some reason I cannot get Bootmod to lock the DME anymore on my laptop (it's a new laptop but I flashed it back to stock from the Stage 1 tune).

[LA430]

Wanted to weigh in here.
2017 430i stage 2 tuned with MG Flasher
Reinstalled factory downpipe.
Flashed back to stock tune and locked ECU.
Passed emissions.
Was able to unlock and reflash stage 1 in the parking lot.