CEL solution? Cat Sim... Micro Cat

[EenyBear]

I know there have been some discussions re O-Cha's (?) cat sim (I haven't seen details, but remain interested...).

I have also seen some DIY versions on other forums that simply involve lengthening the bung to take the secondary O2 sensor away from the exhaust flow, reducing its exposure, and thereby "simulating" a cat. This method seems a little unpredictable to me - but it probably works for some of the people some of the time.

Of course, there are DIY articles here and elsewhere that involve putting fully functional bungs after the secondary cats... but I was looking for an alternative that might remove the need for cats of any description.

I just ran across this site that sells different versions of extensions and a "mini-cat", combining the extension with a wee little piece of catalytic material to satisfy the secondary O2 sensor/ECU partnership.

It seems pretty slick to the uninitiated (like me) ... I could install either an AA or similar header with all the bungs, or add a couple of downstream bungs to a euro header... and put this little device between the secondary bung and the sensor.

Old news? Comments? Off road, competitive use only, of course....

http://www.bigdaddiesgarage.com/?gcl...FRBkhwod-ShL9A

Cheers.

[Mirko]

Interesting ... I wonder if it really works and longevity of the product. I remember reading the O-cha fix might work for 300-500miles and then foul up.

They do work, BUT not with the ones you posted. The issue is that you just do not have the room to install the straight versions that you posted as it makes the o2's stick out too much and hit other components. What you need is this: http://www.bigdaddiesgarage.com/angled-cel-fix.html I personally just installed one of these and it works perfectly!!! The issue that I ran into is that you can only screw in one of these with the header on the car as the second one hits the transmission when you sty and screw it in...

What I did to get around this is to splice the signal wire of the o2 without the 90* o2 sim into the one with it. Works perfectly! I now have a spare 90* sim that I got from the above link so if you are interested shoot me a PM.

BTW I actually did try and get the straight defoulers you posted above to work. There is absolutely no way you can get them to fit unless you have the o2 bongs rewedded on your header.

Post # 9 http://www.m3forum.net/m3forum/showt...&highlight=sim

http://www.m3forum.net/m3forum/showt...light=defouler

[pokeybritches]

There's another way that works on the E9x involving soldering in a couple of resistors. I haven't looked into it enough to see if it would work for the Z4M, but it's what I was going to try first. I would probably use a potentiometer so that I could fine tune the readings.

Link

[Mirko]

Originally Posted by pokeybritches

There's another way that works on the E9x involving soldering in a couple of resistors. I haven't looked into it enough to see if it would work for the Z4M, but it's what I was going to try first. I would probably use a potentiometer so that I could fine tune the readings.

Link

Problem with that was getting the volts to be correct. I stumbled across examples of people using it on M3forum.com while searching the above. Same thing, some work and others don't. Plus you have to splice into your wiring loom which isn't for me.

[pokeybritches]

With potentiometers you can vary the resistance, so you can tweak it to your car's needs. If you have the tools you should be able to measure the exact resistance required. However, I'm in the same boat as far as not wanting to splice into the wiring loom. I haven't looked into it enough to figure out which wires to use, or if it's even feasible.