I have a 97 ES300 with 114K miles on it. I have a CEL with P0420 code, catalyst efficiency below threshold. I have replaced the cat twice with aftermarket ones. In both cases, the CEL came back after a couple of months with the same code. So looks like the previous ones were garbage.
In earlier cases, I had the mechanic install the cat. I don't know which ones he was installing. Now, I want to buy a cat myself and have him install.
For those who have had this problem before, and put an aftermarket cat, can you advice on which is the best aftermarket cat to buy that will work and not bring on the CEL/P0420?
I don't want to put a OEM cat from the dealer as it will cost me $1.5K
+, so I want to settle down with a aftermarket cat, but of superior quality.Please advise which is the best aftermarket cat to buy.
Thank you.