[rowdydaoudy]

I just installed my catless DP on my G80, with the IRL spacers, which did not work. Within 5 miles of driving my CEL came on. (these were 90 degree ones)

Went ahead and bought the recommended BDG ones (http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html) - this is the link I kept seeing, but hoping the 90 degree one wasnt the necessary one.

My CEL has still been on since it popped originally. I am about to install the BDG ones and hoping no washer issues with crushing the honeycomb.

May be a silly question, but asking since so many seem to disappear. Should I immediately clear the CEL when installed or should I wait to see if they disappear on their own?

[Impulse20098]

Originally Posted by Fallenbox

For all of you who have had success with the BDG mini cat - did you use two straight or need to use the 90 for either of the downpipes?

I used the straight..

[breezyrc15]

Ran them for 20k miles with mad catless downpipes and a JB4 and never had a CEL

[BadBoostedBMWM3]

BUMP!

So, I had a custom exhaust built by Patrick (inked custom) for my g80 with Catless DP’s.

I of course purchased and installed the big daddies (BD) garage mini cat adaptors with the supplied washers. Long story short, the CEL came on after about 40 miles and 4 driving cycles.

After reading this entire thread, I definitely feel like the adapters are working somewhat because it held the CEL off for a decent amount of time.

How do you all think I should move forward? Let it do its thing OR I am doomed and the CEL will always be present?

By the way, I have always mixed my own E25 blend with the stock tune.

[Info@mad-us.com]

Originally Posted by BadBoostedBMWM3

BUMP!

So, I had a custom exhaust built by Patrick (inked custom) for my g80 with Catless DP’s.

I of course purchased and installed the big daddies (BD) garage mini cat adaptors with the supplied washers. Long story short, the CEL came on after about 40 miles and 4 driving cycles.

After reading this entire thread, I definitely feel like the adapters are working somewhat because it held the CEL off for a decent amount of time.

How do you all think I should move forward? Let it do its thing OR I am doomed and the CEL will always be present?

By the way, I have always mixed my own E25 blend with the stock tune.

20-40 miles is fairly normal to throw a code. Something doesn't seem right.

Mixing your fuel may have something to do with it but without a code it's anyone's guess.

[BadBoostedBMWM3]

Originally Posted by Info@mad-us.com

20-40 miles is fairly normal to throw a code. Something doesn't seem right.

Mixing your fuel may have something to do with it but without a code it's anyone's guess.

Definitely not what I wanted to hear.

Any recommendations on what to use for a scan tool?

[PhiL_G80]

Probably a dumb question , but do I need to purchase one or two big daddie spacers? Installing catless downpipes on a g80.

[Hit_Apex]

Originally Posted by Info@mad-us.com

20-40 miles is fairly normal to throw a code. Something doesn't seem right.

Mixing your fuel may have something to do with it but without a code it's anyone's guess.

Agree. I'd verify the spacers are installed in the correct location and pull codes. I always run an E85 blend and no codes.

[thompsac25]

I went several hundred miles, maybe almost 1000, before I got a CEL. I checked the codes and they were for o2s. So I dont think they solve the issue.

[BadBoostedBMWM3]

Originally Posted by Hit_Apex

Agree. I'd verify the spacers are installed in the correct location and pull codes. I always run an E85 blend and no codes.

What does that mean, exactly?

I did not clarify, or specify where to install the bungs. That was on inked custom?

Recommendation?

[Hit_Apex]

Originally Posted by BadBoostedBMWM3

What does that mean, exactly?

I did not clarify, or specify where to install the bungs. That was on inked custom?

Here is pic of my BDG mini-cat installed on MAD Fatboy DPs for which I get no error codes and run an E85 blend similar to you. For custom built DPs I'd want to know that the bungs were welded in the same locations as OEM, that the 4 sensors were reinstalled properly (not mixed up), and the BDG minicats were installed on the second bung from the turbo (first bung after the cat location) as shown in the pic. Something seems to be off in your setup, you shouldn't get a code every time after clearing within 30-40 miles. That behavior is the same as having no mini-cat spacers installed.

[BadBoostedBMWM3]

Thank you for those pictures!

I can guarantee that the first 02 sensor is very, very close.

[FrozenBlueG82]

I installed MAD catless downpipes and the big daddies mini cats, with 2 washers as recommended, but got a CEL on the first drive. I cleared the code and it came back on the next drive.

On the plus side, the DP’s sound great.

[FrozenBlueG82]

Originally Posted by PhiL_G80

Probably a dumb question , but do I need to purchase one or two big daddie spacers? Installing catless downpipes on a g80.

Two, one installed on each DP in the rear most bung.

[GolfCoyote]

You can buy these mini cats off Aliexpress for like $5+ shipping.

Seems like whether you spend $5 or $100 they are hit or miss.

[BadBoostedBMWM3]

Update:


My code went away about 40 miles later. I’m very happy!

[Chi58]

Originally Posted by GolfCoyote

You can buy these mini cats off Aliexpress for like $5+ shipping.

Seems like whether you spend $5 or $100 they are hit or miss.

They don’t work and are not the same I’ve got both. One worked and one did not.

[GolfCoyote]

Originally Posted by Chi58

They don’t work and are not the same I’ve got both. One worked and one did not.

I had one that worked fine until I added a catback, then it tripped a CEL.

Edit: One of my buddies also had good luck with the Chinese ones. Like I said, it’s hit or miss on any of these.

[Info@mad-us.com]

Originally Posted by FrozenBlueG82

I installed MAD catless downpipes and the big daddies mini cats, with 2 washers as recommended, but got a CEL on the first drive. I cleared the code and it came back on the next drive.

On the plus side, the DP’s sound great.

Getting a code that quick is weird. I've had people tell me it took a few drive cycles to get a code without a spacer installed.

[Impulse20098]

Originally Posted by GolfCoyote

You can buy these mini cats off Aliexpress for like $5+ shipping.

Seems like whether you spend $5 or $100 they are hit or miss.

Buying anything off of aliexpress is a crap shoot. If someone can not afford $50 mini cats then they do not need to be modding a $100k car. Every car I helped install the catless downpipes and the mini cats have never had a CEL for O2 sensors.

There are a lot of things that can go wrong during the reinstall of the 4 O2 sensors and the 2 mini cats.

However saying that, there are cases I am sure that everything was done correctly, but the car will still throw a CEL. Stuff happens.

In the end if someone is not tuning the car there is no real need for removing the cats. You will not gain a ton of anything but rasp lol.

[GolfCoyote]

Originally Posted by Impulse20098

In the end if someone is not tuning the car there is no real need for removing the cats. You will not gain a ton of anything but rasp lol.

Oh I’m 100% with you on that.

[FrozenBlueG82]

Originally Posted by Info@mad-us.com

Getting a code that quick is weird. I've had people tell me it took a few drive cycles to get a code without a spacer installed.

I’ve cleared it a few times now but it comes back each time after about 5-10 miles.

Normally it wouldn’t bother me, but you can’t remote start with a CEL, which is annoying.