Hello all,

Our family has owned a '79 rx7 for 27 years now, and she's certainly served us well.

Recently we have been having problems with the catalytic converter, however. My dad noticed that after driving it home one night the converter was so hot that it was literally glowing red.

In a panic, he took it in and had the entire muffler system replaced. Now it sounds like a dream, but sure enough tonight he checked and the catalytic converter is STILL glowing hot!

I've done quite a bit of reading online, and discovered that common causes of this problem (aside from the converter itself) can include: faulty oxygen sensor, an incorrect fuel mixture, worn spark plugs or plug wires, a faulty check valve, incorrect ignition timing, sticking float, faulty injectors or other ignition malfunctions.

I'm just wondering if any of you have experienced a similar problem, either with your rx7s or with other vehicles. And if so, how did you resolve it?

In fact, right about now I'm willing to hear any of your theories. What do you think we should do about this problem? What would your next steps be?

Any help or advice would be greatly appreciated. You can reach me readily through email - ghoekstra@gmail.com, or otherwise I will be checking back in with this thread in the coming days.

Thanks everyone!

-gh

 

no but you can just take th ecat out and replace it with a presilencer. Swap the cat back onto your system when you go in for testing. It probably wouldn't make a diff but you should run that anyway it's the more powerful alternative. As for overheating it sounds like your car is just producing too much heat, the cat wouldn't generate it's own heat. Check your engine's colling system for leaks. Also make sure you're getting an efficient aprk (spark plugs are super cheap maybe $8 a piece when there's 4) Check your oil and oil filter as well. Oil helps cool the engine. Make sure the O2 sensor is clean and this could all be done (minus presilencer) for less than $100 or 80 even. It may solve the problem.

 

Hey 87 turbo II.
Has been long time since have done much on older 1st gen 7's but I seem to remember that the 79-80 did not have a cat converter. Was not untill 81 that Mazda started putting the little front cats and big main cat in the exhaust system. The 79-80, I think used a thermal reactor instead of manifold which injected air right around the exhaust as it was discharged to burn all of the fuel left over. There was also a heat exchanger back in the exhaust around where the later cars had the main cat but I don't think it was actually a cat converter with monolith element?? Any of this ring right with you. I was thinking that an exhaust leak allowing too much air in the system might cause that syptom or a carb mixture problem. I wonder which one is glowing red. The thermal reactor right at the engine or the heat exchanger back under the seats area. Tried to do a little digging on the web for more info but did not really find much. Guess it has just been too long ago.

 

yeah I typed that whole thing on basis of 2nd gen knowelege. I realised he was asking about 1st gens, and looked over it quickly to see if I made any fuel injection references. I hadn't so I forgot to check for other tech tidbits like that hehe. You're probably right, I'm not a big 1st gen specialist.

 

greetings
My 91 rx7 lost alot of power coupla days ago suddenly.
someone suggested a prob with the catalytic converter clogged?
help please!!