Catalytic Converter, When Do You Change It?
 

Greetings to all of you Miata enthusiasts out there. My Ebay-purchased 97 Miata is running great (second motor since original had cracked block) and the clock show 193K miles on her chassis. Are there particular sounds or performance issues that will show up when the CAT goes away? Here in CA. we have to have our cars smog checked every other year. This was my year and it took two run ups in order for the numbers to read OK. Would that be a sign of CAT trouble ahead? These may be dumb questions but this is my "Mid-Life Crisis Car" and I am really enjoying it. I am trying to make it last for as long as possible and any suggestions, help would be appreciated.

BTW, has everyone signed up for the 25th. Anniversary Celebration at Mazda Raceway in Sept.? This is a must do event for as many as possible.Those in attendance will be attempting to break a record for the number of Miata's at the event.

If the catalytic converter is original then its performance is certainly less than it was when new. We don't have emissions testing here but I do know that their effectiveness degrades over time mostly due to exposure to certain chemical additives in motor oil.

I've seen advertisements for the 25th Anniversary event and I know it will be very well attended but I won't be going. It's too far for me.

Thanks sixshooter for your response. I guess a new CAT is in my near future. I will go online and try to find that one that won't sink me into deep debt!
As for the 25th. Anniversary at Mazda Raceway, this is a once in a lifetime chance to show who the true enthusiasts are and how far, literally, they will go to illustrate their enthusiasm. For us on the "left coast" it is indeed much easier to attend. I did read online that there are folks in the Bay area willing to rent their second or spare Miata for the event, just in case some folks cannot drive out. As for housing, with hotels filling up fast, there will most likely be enthusiasts near the event willing to take in some Miata enthusiasts just for this event.

Change it when you can't pass smog. Sound like it's about time. Changed mine and my smog went from epic fail to so far below requirements it was ridiculous.

Cheers, Jon

Thanks Jon for your reply. I kinda figured that a new CAT was in my future but being a frugal Scotsman, I really didn't want to pop the coins right now! I guess for the sake of my wonderful Miata I will just have to find an "affordable" unit and get it done!

And thanks for the heads-up on the Miata meet. Just registered.

It's funny that we have 78 different views of this thread but only three people posting. There are so many lurkers on this forum yet so few actually jump in and speak up.

I'm a twenty year old nanny who's currently saving up for my first NA and I love reading forum threads to learn about things I never even knew existed. If that makes me a lurker, I'm fine with that! :)

Lurking is good. Participating is even better. Welcome to the forum!

Good day Tosha-Lyn and welcome to the forum. There are still some great buys out there for NA Miata's, just have someone check it out prior to the purchase!

Thanks!

OK then.....can anyone suggest a good / cheap place to purchase a CA approved CAT for my 97? Going the online route shows that they are fairly inexpensive IF your car is NOT from CA. Otherwise you can figure on doubling the cost here the "land of fruits and nuts"!

Rockauto didn't help?

No luck with that either. They only had them for the Mazda truck line. I did find that O'Reilly's Auto Parts has them at fairly reasonable prices so I will go to my local store and check it out. My main goal is to purchase one that is direct fit so I can do it myself. Hopefully no welding will be necessary.

It will go easier if you soak the studs and nuts holding everything together with PB Blaster for a couple of days beforehand. It really does make a difference.

Thanks sixshooter but what is PB Blaster? Is it a penetrating oil like WD40?

It is more of a penetrating oil than Water Displacement formula attempt #40. It does a better job at penetrating.