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Peter Bagley
Peter Bagley, Toyota mastertech
Category: Lexus
Satisfied Customers: 716
Experience:  master tech at Toyota dealer
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I have a Lexus gs300 2001. I've bought my own o2 sensor and

Customer Question

Hi. I have a Lexus gs300 2001. I've bought my own o2 sensor and I brought it to the shop have them installed for me. After installed the guy he clear my check engine light. So I thought it was fixed. I brought my car to smog few days later and it failed. My catalyst and evap incomplete or not ready. The guy did my smog told me to drive about 25-50 miles and I did came back to smog again and it still not ready.
Submitted: 1 year ago.
Category: Lexus
Expert:  Peter Bagley replied 1 year ago.

Hello my name is ***** ***** thank you for allowing me to help you. Actually there is no set mileage to reset before doing an emission test after clearing codes. The ECU has to go through a driving cycle and may take a day or two of driving. We usually tell our customers to bring it back the following week then we're sure the ECU had time to reset. Unfortunately there is nothing you can do to speed up the process. It's not mileage related but has to go through it's complete cycling process. Hope this helps you.

Customer: replied 1 year ago.
Is there anyway I can do to complete cycling? I been driving for more than 2 weeks and my registration is up soon. Thank you
Expert:  Peter Bagley replied 1 year ago.

Wow that long and it's not ready to test? If not is your engine light on? can you get it scanned for any codes? if all shows clear and working normal then I would suspect an ECU problem. And to answer the question can you speed up the process is no, after driving that long it should be ready if there are no more issues.

Customer: replied 1 year ago.
Yeah I been driving more than 2 weeks. And nope my check engine light is not on. And I did scan my car it said "confirmed there no code to detect" but it's pending p0440
Customer: replied 1 year ago.
I drove my car on the freeway with my scanner earlier. I checked it said catalyst is complete. But my evap still not complete yet.
Expert:  Peter Bagley replied 1 year ago.

oh boy evap problems, that's why it's not resetting you have to repair the evap problem first. It could be any thing until you do a complete active test with the use of a shop scanner on the evap system, without that it will be a hit and miss. the most common issues with a vehicle at that age and mileage are cracked hoses and or vsv valves, a bad filler cap, then the canister itself. An active test will show each pressure and vacuum points at certain situations the system goes through when running thus allowing you to pinpoint the area of the problem., and if the tests show any leakage then you must perform a smoke test. That's putting smoke into the system via a machine to see where the leak actually is. So untill that is corrected it will fail the emission test. Sorry about bad news , hope this sheds some light on your issue why it's not resetting.