ribines300

I purchased a 2000 Lexus ES300 with 150,000 miles few months back. It recently turned the check engine light and the track off light on. It was later diagnosed with error code P0420. I changed the o2 sensor but the light came back after a week. I took the car to the dealership and was told that the bank 1 catalytic converter (the one on the center) needs to be replaced and would cost me $1500. I don't have any drivability issue so I took my car to another place that I trust for a second opinion and was told that they recommend changing all the three converters together because there isn't actually a way to determine which one of the converter is actually bad and was told that it would cost me $3800, which is exactly the price that I paid to buy this car!! But they told me that since there is no drivability issue, I don't have to necessarily change it. But I don't know the pros and cons of it. Any help in this matter is greatly appreciated.

PFB

Check out this You Tube video. Can save you Thousands

ribines300

It seems to be an easy way to check if the catalytic converters are doing what it is supposed to be doing and I certainly can try out this method. Appreciate you taking time to post this video. We don't have inspections here in our state and that's one less thing to worry about even though I'm concerned about the pollution it can cause. But my major concern is, if I don't fix it, will it cause any other issues to any other parts or if it will cause any drivability issues?

PuReChaos

The only issue I could possibly think about is since the cat isn't doing its job most likely the oxygen sensor behind it will fail somewhere down the line which would lead to incorrect fuel trim numbers. This won't necessarily cause drivability issues, but it could potentially hurt your gas milage. Also, there definitely are ways to diagnose which cat is failing by viewing live engine data.