Very interested in a partial (full?) delete and tune after I'm out of CPO. A few questions I have it: will everything look OK/factory on the OBD2 side? In CT they do test emissions by checking the OBD computer and making sure everything looks OK. There is no "sniffer" test for OBD2 cars. Will it pass?

If I were to do a partial delete, what makes sense? What piece of hardware does it make sense to delete first? I ask because ease of reverting to stock if I ever sell it is a concern. I wouldn't want to rip out the tanks and piping for the DEF system.

You may want to read more carefully thru this thread and you will find some answers. Other answers we dont have yet ;)

I had read all 7 pages and I see a member asked about the OBD and emissions about a year ago and he was replied by PM and there was no resolution. I was hoping by now that the people doing these tunes (presumably you and BimmerOEM) would know if the ECU can be coded to make it look like any deleted system is still functioning. Like how the secondary air pump fault can be masked with software on the e39 M5. I would think answering the emissions question is important to most buyers because I don't know many states that don't have emissions testing for cars less than 25 years old.

Regarding partial delete of hardware, I think I'm understanding that
1) DPF delete can give noticeable power and MPG gains.
2) EGR doesn't give as much power gains but will help you have a cleaner engine in the long term, but cannot be deleted without first deleting the DPF.
3) DEF system won't give any power gains but can be deleted with just software.
Is this correct?

Looks like this matter was discussed more on PMs. My idea is that if someone creates a tune that will have all emissions systems deleted and is passing smog legally he will put himself in a very bad position, namely in VAG position. But probably consequences for a small business will be much more life threatening or fatal than for the infamous group. It probably could be done by sending the DDE out of country for re-flashing and the price will be not cheap overall, and i guess at this point most owners that want this will quit chasing this path anymore. It looks like a dead end to me at this time, but other people may have other ideas.

You are deeply mistaken here. First of all it is not a secondary air pump fault, but a secondary air system not enough flow fault. What "tuners" do is to flash a euro tune in the ECU and the euro engines dont have SAS at all. By removing this subroutine in the ECU also monitoring is canceled, but there is a possibility to pass smog test with 1 monitor implausible/not cleared.

This is correct.

OK I guess this may not be an option for people who still need to pass state emissions.
As for e39 SAP... I know what the coding does and may have used the wrong term but my point was there are tuners who can make it pass emissions with a fault in the system.
I'll reevaluate when in another couple years when I hit 100k and something fails :thumbup:

Basically asking the tuner to break laws and do what WV did, trick the system. Yes it can be done im sure but morally and for possible legal actions, most tuners will not do it.
I looked into this as well but NYS emissions put an end to this idea for me.

I guess if someone were to register their cars in a state that doesnt have emissions that may possibly work? Not sure.

Sub'd

I'm struggling to understand why the dpf delete causes more diesel smell. Is the cat part of the dpf?

I had a 1996 ford crew cab diesel dually with the 7.3 turbo diesel. My cat ran away and I regretted not having a better leash every day after that. The smell was terrible.

I understand getting rid of the dpf but not the cat. Help a non-e70 x35d owner understand the relationship between the dpf delete and the smell issues.

Side note: I had a four position switch on the ford; one being daily driving, one being towing, one being for emissions testing (dyno sniffer test) and the last being what I called global warming or block out the sun setting. ;-)

Admranger, good question. Now when i think about it, when the DPF/CAT is deleted, the SCR is disabled too. I will try to activate my SCR again and see if the smell, or most of it, will go away.

I'm new to the BMW diesel terms. Type slower for me next time: SCR = ? :(