Shawn4486

Hi all,

My 1998 ES300 failed smog last week because of a new battery. The catalyst monitor is incomplete and so far I've put over 100+ miles on it. I've been paying special attention to the temp gauge to get the car fully warmed up. I noticed while driving that my temperature gauge goes down about 1 'bar' and back up one 'bar' when I come to a stop (somewhat slowly). Using Torque Pro, my temps go from around 80c (stopped) to the mid 70c to high 70c range (moving).

Is this normal or could I have a faulty thermostat? Do I just need to keep driving the car until the self check completes, and if so, does anybody know how long this might take?

Thanks!

PFB

The temperature swings could be a lot of things. Thermostat is just one of them, defective fans, partially blocked radiator are some others.

In terms of the Monitors not ready, it's not just how far you drive, but also how many times you shut off the engine, as well as several other considerations. Give it more time.

minivaka

Hi Shawn,
I am currently having the same issue with my es300 1998 lexus. Your post was a few years ago so I hope it all worked out! Any updates on how long it took for the test to run complete? Or any other notes about this issue?