PearlLex

I had been having problems with my check engine light coming on. Then I reset it and it would stay off 100 miles or so then come back on. Tonight after about 1000 miles of being on, it went away. Is this common and will it come back on?

Lexus007

Weird i had the same problem one night and the next day it went away too. I dunno maybe a faulty sensor? I dunno can anyone here help us out? Btw my 1998 es300 has 45,000 miles on it.

spray004

How did you reset your check engine light? Did you reset it by disconnecting the battery? If you did that step then you reset your whole computer. When you reset your whole computer, your computer has to "relearn" everything. Once it has, it will read that there is still something wrong with your engine. Make it easy on yourself, if it comes back on, then take it to Autozone and have them run a scan on your engine. Even though 99.9% of the ppl at Autozone are idiots, its not hard to read an engine scan tool. Your check engine light doesnt have to be on for there to be a problem with your engine.

flipside909

It would probably be best to get the code scanned. It could be a simple as a loose MAF connection or emission system failure i.e EGR equipment, sensors or etc. have it checked.

PearlLex

so i should still run a check even though the light if off? autozone said they didn't have the right tool to run a scan on my 96.

lexusk8

In that case, you have no choice except to go to a Toyota or Lexus dealership to have your car scanned for error codes. They may not be able to run the test if you can't replicate the check engine light in front of them, but be ready to fork over a $80-$90 diagnostic fee if you go through with this.

spray004

Did you talk to someone that knew what they were talking about? Unless Toyota wanted to be different, all '96 and newer model vehicles regardless of make use an OBD II computer system. Autozones are "supposed" to have an OBD II scanner to clear codes and trouble shoot problems. If for some reason they don't have this type of system, Lexus or even Goodyear can help you out. They have the equipment that will scan your engine without the light being on. Autozone can only check your engine if the light is on.

PearlLex

my diagnostic tester is circular. autozone has a rectangular tester.

flipside909

Wow really? Can you take a pic of it. I've never seen a circular diagnostic plugin for 1MZ-FE's. Your diagnostic plug in is located by the intake plenum right?

PearlLex

the tester is under the dash but i found the rectangular one by the fuse box. autozone ran it and it was the o2 sensor.

spray004

His was the OBD II system.

aimsoft

Pearlex,
Did you get any quote for repair ? I have similar problem on my 98 ES300. The OBD scan said P0135. The dealer still wants to replace the Air.Fuel sensor. They quoted me 664 for parts + 290 labor = 964$ Total... I made them reset the OBD code once, but the light came back up after 20 miles.

I wish there is any way to just turn that light off permanently

flipside909

That's not a good idea considering it's linked to many other components to your engine.