Hello all,

I'm looking to have to replace my Cat (Catalytic Converter). I've done a pretty good job of reading the past posts regarding this. Some pretty recent. Seems like the price of cats has gone up quite a bit. Earlier this year, a thread posted a cost of the cat around $400 at Autozone and I look it up and it's over $600! I just saw that Doctor J stated that the state may be able to help out on the cost of repairs. Which is news to me! I'll be looking to see if I can qualify.

I guess the ~$100 cats on ebay is a no go? I do want to get a legit cat that would not just be continuing headaches. Just don't want to be handing out >$2k to get the gold plated dealer's cats to get matters done.

One thing is none of the posts really address the sensors. I'm pretty sure my senors are working just fine as they are turning the "check engine light" off and on on the dash. Currently it looks like the light is staying on for about 200 miles. Then is goes off for about 50 miles and then repeats. So I'm thinking my sensors are good. Do they get taken off and put on the new cat? Do people put new sensors on the new cats? Seems like for >$2k, the gold plated one would have new sensors on it, right?

Thanks for any and all replies regarding this issue.

 

I did the same thing last month. Needed a cat and couldn’t find anything reasonable. I ended up going with this and it works for smog. Dealer only comes with cat no sensors. Hope this helps.

 

Scanner and 5 gas analyzer are helpful to determine if cat is working. Scanner should read the secondary O2 sensor output which should vary very slowly (least reliable test requires comparison to the car with good working cat) and cat temperature (often goes to 500 degrees C)
5 gas analyzer will read CO and NOx; again these values must be compared to the car with good working cat, with SAME weight and similar engine size (perhaps Toyota Yaris?)

 

Thanks for the help. I'm a bit confused. How did you make this work? It clearly states here, "Not legal for sale or use in the state of California." So this passed smog? Did it come with sensors? What did you do on the sensors?

 

The O2 sensor is one of the sensors on the system? I saw that Rockauto had them for about $20 on clearance. ........

These are two sensors in question correct?

https://www.rockauto.com/en/moreinfo...716&cc=1433357
and
https://www.rockauto.com/en/moreinfo...894&cc=1433357

 

It's called downstream O2 sensor. First step is to get a scanner and read the cat temperature. It can be around 250 C at idle and 550 C under load

 

Sorry for the confusion. The part # circled in red is the CA compliant. I use the same old sensors that were in my straight pipe. No more check engine light.

 

OK thanks. BTW, the "Additional Parts Needed: 31387, 31383" are the gaskets?

 

yes, they are.

 

Thanks for the info Chris.
Is the cat still working / not giving a check engine light? I ask because it went from $297.99 to $657.99: