Hello guys, I am a long time lurker on these forms...lol. I have gain lots of useful information over the years. Changed my spark plugs 5K miles ago after I had a misfire in one of my rotor housings. A few days ago I started having intermittent power loss and a very rough idle, after taking my car to the dealership they said I needed new coils and wires. All has been well, the car runs like it is new again. Today though I got a CEL again and after a second trip to the dealership I found out I have a dead catalytic converter. I am being told that all the unspent fuel being dumped into the exhaust because of the misfires killed the cat. I am 1300 miles past my 80K emissions warranty...the dealership wants nearly $2K to replace the cat.

After a bit of research I found an equivalent converter at Auto Zone for about $220, right now I am leaning towards getting it and getting a local mechanic to put it on. I would just go catless but don't want to always see a CEL since I won't know if something else is wrong. My second option is to get an exhaust shop to weld in a "universal" converter...from what I understand this is my cheapest option. What would you guys do?

 

Honestly.. If you don't get tested for it and can tolerate the smell, gut it.

That $220 cat (+labor install) probably won't last very long. You can spend a little move and get a high flow cat from rx7store.net. But it won't last forever either.

 

Interesting, if this is the case does that mean that there is something special about the OEM Mazda cat? I was beginning to wonder why it cost $1000...lol. Exactly how long should I expect a $220 cat to last?

 

It should last about 220 yards. Maybe 220 miles.

This isnt a massive dealer markup item, as it really does have platinum inside. Our exhaust temps are 1,300-2,300 degrees, piston powered cars are only 800-1100 degrees. Our heat will destroy a normal cat in short order. Go take a look at the BHR midpipe thread, recent page, for what less than 100 miles of driving with 1 auto-x session did to a Davesport cat.

The only cheap option is finding a used oem cat, if you absolutely have to have one at all.

 

Are you sure it won't last 500 yards? That makes a lot of sense...I forget rotaries run much hotter. I would consider a midpipe but don't want to stare at that stupid CEL, is the accessport the only way to turn permanently get rid of the CEL?

 

Yup

 

many people sell used cats for cheap here.
Or, call a local auto-wrecker to see if they have any from an 8.

 

The more I think about it getting a used OEM part seems like the best way to go. After doing more reading here it seems I'll be lucky to get 20K miles out of an aftermarket one. I guess all that platinum makes a difference, if I can't find a used oem one I guess I have no choice but go with the aftermarket. I could always replace it when I find an oem one to buy...

 

I just posted an add in the wanted section on here, I will check with some local scrap yards tomorrow to see if I can find a wrecked 8. Anybody have a clue how long I can go with things the way they are without screwing something else up. If I can wait to find a used oem unit I would prefer to do that. Otherwise I will have to use an aftermarket temporarily...

 

How do those rx7 store cats hold up?

 

Do not drive your car around with a bad cat, at all.

When you went in for the bad coils and wires were you still within the 80k mile warranty for the cat at that point? From what you said it sounds like the dealership admitted that bad coils/wires killed your cat, and if that was more than 1300 miles ago then they also just admitted that your cat was bad while it was still under warranty. Some people have had some luck getting a free cat if they can show they had issues before the warranty was up, and that it was indeed the cat at that time.

 

$220 plus labor for POS autozone cat....
or buy a Cobb AP, mask the cel after bashing out the insides of the cat, get a good tune and put some power back to your wheels.
easy to see which to pick

 

I've read mixed results, if you go to google and type: "site:rx8club.com rx7 store cat"

you will see some threads on it.

If I ever do get a cat again it would be this one or a used oem one.

 

I was not under warranty when I went in for the bad coils and wires. A few months ago I had a misfire cel (back at about 77K miles), I changed the plugs and the problem went away. Last Friday my idle got really rough and I got a flashing cel, dealership changed coils and wires and all was well. The next evening I got a cel again and after a second visit to the dealership I was told I had a bad cat.

 

The 220 dollar one that you spoke of from autozone has a 5 yr warranty if I remember correctly, so if it doesnt last that long its a free replacement, I got the same on installed in my car currently due to low budget. I changed it out myself as well its a fairly easy job that can be done yourself

 

Finally, someone who has given that one a try! How many miles have you driven with it on? Any CEL's? So far I am having pretty good success in my search for a used oem one, if for any reason that doesn't work out I may use the Autozone one as a temporary replacement.

 

well I didnt want to use the one from there, but money said I had to lol...but I havent put any miles on it yet because I am still working on it, turned out that I have to replace my muffler as well...but if ur cat it bad, you might want to make sure its not the same as mine, just to be safe ya know

 

I've never had a cel issue regarding a blown out cat. My first cat started showing signs of deterioration by 50k miles (listen to the rattling bits in the exhaust system). It wasn't until about 60k that everything inside was blown out the exhaust (i mean completely empty cat). I couldn't stand the exhaust anymore so I took her in. The service manager thought somebody gave me an empty unit (lol). Which was fine by me because they replaced it for free. Somehow the current one is still good, considering my mileage has more than doubled since.

 

What happened to your muffler?

 

Well that explains the rattling I was hearing...lol.

 

I dont know what happened to the muffler, all I know is that my cat would still glow red afer installing the new one even, but after I disconnected the new cat from the muffler it ran and idled just fine, still dont know, I will cut it open and find out some other time

 

Interesting...my cat never glowed but it did make a rattling sound. I wonder if part of the material inside your cat got lodged in the muffler...