Possible solution for CEL when using headers on 2000+, an O2 spacer with a mini-cat..

[steved0x]

My son is having a 420 on his 99 Miata - Catalytic Converter not operating at efficiency (paraphrasing...) Apparently this is common on 99-2000 Miatas. it has a new cat but this code is still popping from time to time.

While researching on the Miata forum some folks have had success with an O2 spacer, that has a mini CAT in it.

O2 Simulator Mini Cat Cel Fix best oxygen sensor simulator made.

I thought it was just going to be another spacer (and this vendor sells the spacers too) but it has a little honeycomb of catalytic converter material in there.

I know some boxster folks get a CEL when putting in performance headers because they lose the first set of cats, and the performance headers with the sport cats are super $$$, so I thought I would pass that along.

I may buy this for my son's Miata but first I am going to make sure that the other causes are eliminated (exhaust leaks and so forth), but I just wanted to pass it along.

Has anyone ever seen or used anything like this before? Is the regular spacer usually good enough?

Thanks

Steve