Hey guys, not an rx7, but a Millenia S
 

I just bought a 99 Millenia S with around 92,000 on it. However the chekc engine light is on, I pulled the code and it says po431. Turns out this is my catalytic convertor. How many cats does the millenia have? heard it was an expensive fix form the dealer. Autozone carries the cat for not alotta money. Just wondering if this is an easy fix and how much it'd cost me if i did it through a local mechanic.

I am new to mazdas. I also own a 90 Eclipse GSX (AWD turbo) with alot of goodies in it, and I dont even have a cat on it (running 3 inch turboback pipes). How long can i run with this CEL safely?

thanks

Chet

I own a 95 Millenia, but not a S. My check light has been on ever since I bought the car. Been driving with the light on for over two years and runs great. I think it's the o2 sensors gone bad, but cost over $150 each and need 4. Thanks

My wife has a 99 NA millenia and I believe it has 1 or 2 cats...never really looked. IT shouldnt be a big deal...I'd just go to the local muffler shop and get them to weld one in.

Now, you can have a code for the cat that actually means there's a problem with the rear o2 sensor being bad. The way this works is there is one o2 sensor in the front, before the cat, and one more behind the cat. The computer compares their measurements, expecting to see less from the one behind the cat. If the back one reads too high of a level, it sets off the code for the cat. So you can see that a bad sensor here could also lead to the code.

The only issue my wife's car has had was the transmission at 70k (and it's starting to act up again at 125k) and the EGR code (the passage clogs with carbon and must be rodded out periodically).

From what I am told the millenia S trans is different and is actually stronger than the one for the NA 2.5, which is basically a 4 cylinder transmission forced into v6 service in a noticeably heavier chassis.