[ocN55]

Can those who are running a catless dp (VRSF, ER, VM, etc) on a stock car share what kind of O2 spacer has worked for them?

I'm hoping to consolidate a sample size large enough so that people could make an better decision between L and straight spacers. Also, it would be awesome if people could post pics of what worked and what has not worked!

Here are examples of the shapes:
L - https://www.amazon.com/gp/product/B0...=AZZQLCSVQ753J
Straight - https://www.ebay.com/itm/Blox-Racing...-/301947480064

[ocN55]

Calling B58 owners!

jalkster
Joego123
PushingRedline
F30MGM
kern417
wassy4

[ocN55]

awilki0101

[ocN55]

240zman

[paimon.soror]

Dont forget about J spacers lol

https://www.amazon.com/Vibrant-11619.../dp/B00AQ7972O

I have one of these because i heard great things about their compatibility from the Porche community, unfortunately never got a chance to try it.

[kern417]

I don't have a downpipe on this car, but a straight spacer worked on my previous car. I don't know the brand since I got it from a friend for free. the CEL didn't come back for 20k+ miles.

However the J/L spacers are the best option if you want to be sure it works the first time. it is better at keeping the CEL away and easier to fit since a straight spacer makes the 02 sensor stick out really far and may be close to hitting the body of the car or other components in the engine bay.

Just don't go paying $50 for a billet etched carbon fiber blah blah blah spacer. They all do the same thing and can be had for $10 or less.

[jalkster]

I still run the blox racing one you posted. over 20k miles now and no CEL.

[Mike@N54Tuning.com]

There are a few people out there running spacers with success.. I was actually surprised they worked and worked for an extended period of time without a CEL.

Mike

[kern417]

Not sure how hard it would be, but it would be cool if the aftermarket companies integrated a J into the 02 sensor bungs on the downpipe to make it full proof and we don't have to buy an extra component to make it work. even if the welded the J inside the downpipe so that exhaust gases flowed past it, it would probably work and no obvious modification from the outside.

[wassy4]

Mine is an L shaped and two straight spacers stacked on the long end - don't do this. O2 will read nothing instead of something and you'll get a CEL anyway. Run either one straight spacer or two stacked together but I think L is too long.

[Jerich0]

I have 42 Draft Designs O2 spacer, works beautifully and gives me cat reading at full efficiency 655%

[ocN55]

Originally Posted by Jerich0

I have 42 Draft Designs O2 spacer, works beautifully and gives me cat reading at full efficiency 655%

Awesome!
Could you explain what the 655% reading means though?

[Jerich0]

Originally Posted by ocN55

Awesome!
Could you explain what the 655% reading means though?

If you have a OBD reader with the OBD Fusion app or similar you can check mode $06 under “monitors”... there you will be able to monitor secondary sensor performance among other things.


655% reading is what measures cat efficiency... 100 is min 655 max if you dip below 100 you get a cel right away...

In order for the spacer to work consistently you want to be above 400ish

[ocN55]

Originally Posted by Jerich0

If you have a OBD reader with the OBD Fusion app or similar you can check mode $06 under “monitors”... there you will be able to monitor secondary sensor performance among other things.


655% reading is what measures cat efficiency... 100 is min 655 max if you dip below 100 you get a cel right away...

In order for the spacer to work consistently you want to be above 400ish

Gotcha...
It looks like the spacer you're using has some adjustability. Do you mind sharing how you adjusted it?

[Jerich0]

It is adjustable but I got it in the closest setting... this is perfect because I still keep a very low rich/lean delay without affecting catalyst efficiency readings which need to remain above 400...

I also have an 18 M3 with the S55 engine, it comes from the factory with high flow metal cats and it ranges around 400-500% but has secondary cats to take care of the rest.

The B58 is pegged at 655% stock, which shows you just how restrictive the factory cat is since its actually ceramic, these tend to “clean” the air a wee bit more at the cost of flow and cat life span.

As always YMMV.

[awilki0101]

finally put downpipe back on car and swapped spacer with this one and so far after 300 miles no light. Normally would have had one or two pop up by now

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[F30MGM]

I use the L shape one no CEL still ^^

[ocN55]

Here's what I ended up with. Had it for 500 miles, never saw a CEL

[SCRPN]

Originally Posted by Mike@N54Tuning.com

There are a few people out there running spacers with success.. I was actually surprised they worked and worked for an extended period of time without a CEL.

Mike

Sorry if this is a dumb question, but what would cause the spacer to eventually give a CEL? I would assume if the life of the downpipe in the car WITH an O2 spacer, it should ultimately be showing a consistant cat efficiency percentage?

[Bfifty8]

I just bought two small ones from oreilys and stacked them to make one. Zero issues for about 8000 miles or so

[SCRPN]

Anyone from NY know how affective/reliable this is toward yearly inspections?

[ocN55]

Originally Posted by SCRPN

Anyone from NY know how affective/reliable this is toward yearly inspections?

Assuming it's just OBD, it should be find