I saw someone mention that if your rex has 80k+ miles, and still has the stock cat its probably plugged up or something. What i'm wondering is how i can check for that. I just bought my rx-7(89 N/A with 83k miles) and am trying to get everything back to good running before i start putting on aftermarket parts. Thanks

journey

 

Well, it may still be fine. Ofcourse Mine was clogged at about 97000 miles.

Anyway, to check it's pretty simple. You can start by tapping it with a rubber mallet. If you hear rattling...kinda sounds like rocks are in it...then it's bad. You can also just unbolt it and look inside it. It will be very apparant if it's clogged or not.

Hope this helps.

 

A mechanic told me that if they were clog, after a long drive they cats will be red hot. but I don't know if this is correct.

 

Yes, I had mine grew red for 30 min after i shut it off

Actually its not hte cat thats cloged first. Its the pre cat that goes first, then takes out the big cat

 

You mean that horrible sem-backfire and rattling noise when I fire it up is coming from the Cat, damn, another $300 gone on the bloody car - mine doesn't have any pre-cats [87 n/a] is it cheaper to buy a generic cat and have it welded in place or will this affect performance? I'm thinking of getting a header and downpipe from the wreckers and running without a Cat at all after my emmissions test next month - will this work if I leave the o2 sensor in place or will it screw up the 6-port pressure?

 

No cat stinks, especially when you have an exhaust leak. I just forked out 350 for a bonez, its in the mail now