Downpipes CEL Question

[eDubz]

Hey guys, I'm thinking about doing the VSRF downpipes but I have some newb questions...

I have the Velos tune and I know it tunes out the CEL, but I can't pass emissions with the Velos tune installed (the O2 system shows as "not ready" so it consistently fails).

So I need to figure out a way to have no CEL with the downpipes and a stock tune.

I'm assuming I should use a spark plug O2 non-fouler on the second O2 sensor, but I'm looking for someone to confirm.

If so, can you send me a link to the non-fouler you used? Or will any non-fouler work?

Appreciate any insight!

[Molez93]

Are you 100% on the monitor situation with the tune? I've had two different Velos tuned X5Ms pass NY inspections (which require OBDII readiness, perhaps with one allowance for a non-critical monitor being off-line). My only challenge along those lines was when I did the first install, I let the shop skip doing the O2 sensors correctly. It ran poorly and with a persistent CEL until we had everything connected properly. Ran great and passed inspection after that.

[eDubz]

Yes, 100% sure. I had a long battle with this...failed emissions about 8 times, dealership couldn't figure it out, etc.

Finally had the thought that it could've been the tune and flashed it back to stock and it passed right away.

Here's a thread on it -

Failed Emissions https://www.xbimmers.com/forums/show....php?t=1639489

[pearlpower]

I need to reinstall my downpipes shortly as I have smog coming up within a month. I will also flash back to stock. I get a constant CEL, even with extenders, nonfoulers in the plugs.

[Dawgz]

Are you sure your Velos tune has the downstream cat sensors deleted? Because i have Velos and mine are deleted and show ready.

[mhkm]

I also have the velos tune and catless downpipes and never had a CEL.

[eDubz]

Originally Posted by mhkm

I also have the velos tune and catless downpipes and never had a CEL.

Yes, they tune out the CEL, but have you tried to pass emissions with the tune on?

When the Velos tune is applied, I fail emissions due to the cat and O2 systems showing as "not complete".

I'm sure if I add the downpipes, I won't have a CEL, but will still fail emissions due to those systems showing "not complete".

So the question is - why do those systems show as "not complete" with the Velos tune installed, but immediately show as "ready" when I install the stock tune?

I reached out to Velos to get their thoughts.

[eDubz]

To reiterate the root of my question...is it possible to have a stock tune, no CEL, and catless downpipes?

That would solve my problem because I could just flash back to stock when I need emissions tested (like I do now).

[ryansbmw]

You can try the spark plug defouler but its no guarantee it will work.

https://www.fabspeed.com/universal-o...verter-single/

Before companies built spacers with catalytic material placed inside, I built my own for my E39 ( had headers and euro sport cats installed) and it worked. I passed inspection here in NJ without issue.

[Sophisticated Redneck]

I don't think the non-foulers work, and tried then and still got a CEL. I haven't tried these yet but this is probably the only way to do it if you live in a state that requires every monitor to be active:

https://www.magnumtuning.com/en/deta...ect-box-anchor

[Dawgz]

I have the Velos tune as well and I just ran the emissions check and my monitor shows INC.

This will surely fail if I went to get it checked.

[Dawgz]

Originally Posted by Sophisticated Redneck

I don't think the non-foulers work, and tried then and still got a CEL. I haven't tried these yet but this is probably the only way to do it if you live in a state that requires every monitor to be active:

https://www.magnumtuning.com/en/deta...ect-box-anchor

This does seem like the only way.

[eDubz]

Carlos from Velos called me yesterday (on a Saturday, always great service). He suggested 200 cell catted downpipes.

I'll probably just end up doing the Megan exhaust for some added sound.

I realize it won't give me the performance upgrade I'm looking for from the downpipes, but it is what it is.

[Dawgz]

Originally Posted by eDubz

Carlos from Velos called me yesterday (on a Saturday, always great service). He suggested 200 cell catted downpipes.

I'll probably just end up doing the Megan exhaust for some added sound.

I realize it won't give me the performance upgrade I'm looking for from the downpipes, but it is what it is.

You'll still need a different tune file tho right? One that doesn't delete the post Cat sensors

[eDubz]

Originally Posted by Dawgz

You'll still need a different tune file tho right? One that doesn't delete the post Cat sensors

No because you can just flash it back to stock and pass emissions with a 200 cell cat. Then flash it back to the tune after you pass emissions.

[Dawgz]

Originally Posted by Sophisticated Redneck

I don't think the non-foulers work, and tried then and still got a CEL. I haven't tried these yet but this is probably the only way to do it if you live in a state that requires every monitor to be active:

https://www.magnumtuning.com/en/deta...ect-box-anchor

Which non-foulers did you try?