[Myn54isSLOW]

I've spent at least 5 hours on the forums reading about how people passed inspections with Stage 2 tunes, catless downpipes, JB4, Cobb, etc... It's a bit confusing to me because some people need a DP fix to pass inspection (which are hard as hell to find) and some don't. I'm planning on putting my downpipes in next week... but before I do that I want to make sure I can pass inspections one way or another. It is important to note that N.C. allows at most 1 monitor to be not ready. With that being said... How did you guys pass inspections?

[jwalker87]

On my 2008 335i (with the N54) with JB4 and a catless DP, I use a BMS DP Fix and it works just fine. It is required to pass PA emissions, which is OBD-II only and sounds similar to your NC emissions test. Same 1-monitor-not-ready requirement, but mine all get to 'ready' once I run through a drive cycle. As for availability, can't help you there ...

Another thing to note is that my 2011 335i (with the N55) has a BMS BEF (via Cobb AP) as well as a JB4 and a catless DP. Nothing further is required for it to pass an OBD-II test; must be something with the BEF? Not sure if this would apply to your 335is as well, but it's something weird that is VERY convenient for me!

[Myn54isSLOW]

Originally Posted by jwalker87

On my 2008 335i (with the N54) with JB4 and a catless DP, I use a BMS DP Fix and it works just fine. It is required to pass PA emissions, which is OBD-II only and sounds similar to your NC emissions test. Same 1-monitor-not-ready requirement, but mine all get to 'ready' once I run through a drive cycle. As for availability, can't help you there ...

Another thing to note is that my 2011 335i (with the N55) has a BMS BEF (via Cobb AP) as well as a JB4 and a catless DP. Nothing further is required for it to pass an OBD-II test; must be something with the BEF? Not sure if this would apply to your 335is as well, but it's something weird that is VERY convenient for me!

Oh okay. I currently have MHD installed. I've been thinking about going with COBB because I saw a couple of people in the forums have the same luck as you with your N55. I can justify paying $650 for the APv3 if I don't have to worry about inspections every year! But the success stories are so sporadic that it scares me lol.

[Welcome to NBA Jam]

DP Fix

[Myn54isSLOW]

Originally Posted by Welcome to NBA Jam

DP Fix

Where did you get yours from? Do they still offer it?

[jwalker87]

Originally Posted by Myn54isSLOW

Oh okay. I currently have MHD installed. I've been thinking about going with COBB because I saw a couple of people in the forums have the same luck as you with your N55. I can justify paying $650 for the APv3 if I don't have to worry about inspections every year! But the success stories are so sporadic that it scares me lol.

Agreed - I was surprised when it happened to me (had been researching how to get the N55 to pass emissions), and just randomly decided to hook my reader up and see what it said - voila! I researched more afterward and could find no information regarding that the BEF did this, so it's either incidental or very hush-hush

I'd say your best bet is still to try to find a DP Fix. Alternatively, I think it's just a rheostat, so with some info you could make your own?

[Myn54isSLOW]

Originally Posted by jwalker87

Agreed - I was surprised when it happened to me (had been researching how to get the N55 to pass emissions), and just randomly decided to hook my reader up and see what it said - voila! I researched more afterward and could find no information regarding that the BEF did this, so it's either incidental or very hush-hush

I'd say your best bet is still to try to find a DP Fix. Alternatively, I think it's just a rheostat, so with some info you could make your own?

I'm not that savvy when it comes to these types of things. Especially something that I'll be plugging into the DME 😂

[jwalker87]

Originally Posted by Myn54isSLOW

I'm not that savvy when it comes to these types of things. Especially something that I'll be plugging into the DME ��

I found this with a bit of googling - just in case you find someone who is willing to physically make it

Edit: UGH the forum is blocking the hyperlink. Remove the spaces below ...

https://www.b o o s t a d d i c t.com/showthread.php?53622-Make-your-own-oxygen-sensor-tuner

[dpaul]

Originally Posted by Myn54isSLOW

I've spent at least 5 hours on the forums reading about how people passed inspections with Stage 2 tunes, catless downpipes, JB4, Cobb, etc... It's a bit confusing to me because some people need a DP fix to pass inspection (which are hard as hell to find) and some don't. I'm planning on putting my downpipes in next week... but before I do that I want to make sure I can pass inspections one way or another. It is important to note that N.C. allows at most 1 monitor to be not ready. With that being said... How did you guys pass inspections?

For any state that allows one monitor "not ready" you don't need a DP fix. There are good reasons to avoid the DP fix (besides the expense and hassle) which you can read about in other threads.

You just need your tune to disable the cat efficiency monitor so that it never becomes "ready". The MHD flashing device does this by default but the JB4 piggyback does not. The JB4 software used to allow the option but Burger removed it due to liability concerns.

if you are using MHD to flash, just make sure that the "OEM/Catted downpipes" checkbox is NOT selected.

As long as your other monitors are set and no one makes a visual inspection for cat removal (not common outside of CA), you will pass. Sometimes the other monitors, particularly DMTL (evap) will refuse to become "ready". So you must verify with MHD or OBDII scanner that all except cat efficiency are set before you go for inspection.

[dpaul]

Originally Posted by jwalker87

Agreed - I was surprised when it happened to me (had been researching how to get the N55 to pass emissions), and just randomly decided to hook my reader up and see what it said - voila! I researched more afterward and could find no information regarding that the BEF did this, so it's either incidental or very hush-hush

I'd say your best bet is still to try to find a DP Fix. Alternatively, I think it's just a rheostat, so with some info you could make your own?

Yes, you can make your own. It is basically a voltage divider (i.e. two resistors in series). A potentiometer (rheostat) is used for that purpose rather than fixed resistors so that output can be adjusted to a level that the DME "accepts". The idea is to take the voltage output of the pre-cat sensor, lower it to approximate what the post-cat sensor would normally report if a cat was present, then use it to spoof the DME. There are a couple of other components involved but it's really very simple. The hardest part of making it yourself is sourcing the pins for the DME connectors.

But you really don't want to leave it in place for long periods of time. The short explanation is that the DME depends on the outputs of the narrow-band post-cat sensors for calibration of the wide-band pre-cat sensors. If you leave the DP fix in place for long periods you may see trims drifting to unacceptable levels and possibly driveability issues. Not everyone reports this but enough do to make it a concern.

[Myn54isSLOW]

Originally Posted by dpaul

For any state that allows one monitor "not ready" you don't need a DP fix. There are good reasons to avoid the DP fix (besides the expense and hassle) which you can read about in other threads.

You just need your tune to disable the cat efficiency monitor so that it never becomes "ready". The MHD flashing device does this by default but the JB4 piggyback does not. The JB4 software used to allow the option but Burger removed it due to liability concerns.

if you are using MHD to flash, just make sure that the "OEM/Catted downpipes" checkbox is NOT selected.

As long as your other monitors are set and no one makes a visual inspection for cat removal (not common outside of CA), you will pass. Sometimes the other monitors, particularly DMTL (evap) will refuse to become "ready". So you must verify with MHD or OBDII scanner that all except cat efficiency are set before you go for inspection.

Thanks for explaining it. So as long as the "OEM Catted DP" is checked the monitors will eventually be ready once the drive cycle is complete. There is no need to flash back to Map 0 or Stock correct?

[dpaul]

Originally Posted by Myn54isSLOW

Thanks for explaining it. So as long as the "OEM Catted DP" is checked the monitors will eventually be ready once the drive cycle is complete. There is no need to flash back to Map 0 or Stock correct?

Yes - but in case this is not clear, if you have removed the cats, as soon as the monitor becomes "ready", it will detect the lack of cats and you'll get a CEL.

If you have removed you cats, you must not check that box. If your other monitors are OK, it doesn't matter which map you select, you will still pass with one "not ready" monitor.

[Myn54isSLOW]

Originally Posted by dpaul

Yes - but in case this is not clear, if you have removed the cats, as soon as the monitor becomes "ready", it will detect the lack of cats and you'll get a CEL.

If you have removed you cats, you must not check that box. If your other monitors are OK, it doesn't matter which map you select, you will still pass with one "not ready" monitor.

Okay... last question for you.

I've heard that O2 sensors are prone to being damaged due to the excessive flow through the catless downpipes. Would you still recommend adding a spacer to maintain its longevity either way or would that cause issues?

[dpaul]

Originally Posted by Myn54isSLOW

Okay... last question for you.

I've heard that O2 sensors are prone to being damaged due to the excessive flow through the catless downpipes. Would you still recommend adding a spacer to maintain its longevity either way or would that cause issues?

NO! this is completely untrue (well, untrue when the factory arrangement of twin turbos is retained). In addition, spacers will affect the response of the sensors in a way that the DME will not like. Even though the monitor is disabled, the DME is still listening to the post-cat sensors and uses them in the manner I described in one of the posts above.

Edit: I will add that O2 sensors are prone to being damaged when downpipes are replaced by those who over-twist the leads or let the removed sensors get whacked with a tool

[nsjames]

the reality is that the post cat o2 sensors will probably see less heat now that the catalysts are removed.

[opjose]

Originally Posted by dpaul

Yes - but in case this is not clear, if you have removed the cats, as soon as the monitor becomes "ready", it will detect the lack of cats and you'll get a CEL.

If you have removed you cats, you must not check that box. If your other monitors are OK, it doesn't matter which map you select, you will still pass with one "not ready" monitor.

You will pass as long as the "not ready" is not related to the O2 sensor or cat.

The whole reason for the inspection is to make sure your cats are doing their job so a not ready on the cats results in a fail.

Been there, gone through that.

[dpaul]

Originally Posted by opjose

You will pass as long as the "not ready" is not related to the O2 sensor or cat.

The whole reason for the inspection is to make sure your cats are doing their job so a not ready on the cats results in a fail.

Been there, gone through that.

For most states, I believe what I stated is true. The particular monitor that can be "not-ready" is not specified. In several states, "continuous" monitors must be set but the cat efficiency monitor is in the "non-continuous" category.

So your experience indicates that MD has different criteria than most states.

To your point, I think it's likely that more states will smarten up about the way people are circumventing the rules. But right now, I can state with certainty that MA, NH, PA, CT, NY will pass you with one monitor "not-ready", regardless of the type of monitor. I looked on-line for NC and found nothing to suggest that cat efficiency was excluded from the one monitor rule.

Edit: Small point but cat efficiency is not the "whole reason" for OBDII emission testing - DMTL is about emissions as well.

[SRAcork]

I'm not familiar with any other state. But another thing to look at is a physical inspection. I ran into this problem in Ma. They usually don't check anything but I was low on washer fluid. Being a top mount single turbo they instantly realized I had a modified car and checked underneath for a cat. I ended up having to buy a cat and punch out the inside. Just slipped it over the exhaust and welded it in place. Again, I don't know your state's laws but might be worth making sure you're completely covered if they check.

[opjose]

I have never done an inspection in MA but the state documents imply that all O2 monitors must show ready.

See: https://www.mavehiclecheck.com/motor...info#Emissions

The EPA "bible" is available here


https://nepis.epa.gov/Exe/ZyPdf.cgi?Dockey=P1002KRN.pdf

On interest are the notes in appendix E which deals with readiness results.

If a vehicle has previously thrown a DTC code and comes back with O2 or Cat not ready that results in an instant fail.

The longer EPA documents go into why OBD2 testing focuses on cats and O2 as a means of gauging emissions contaminant levels.