You are here:

Toyota Repair/97 Land cruiser smog


My 97 land cruiser runs fine.  I just took in for smog and the O2 sensors and catalyst will not reset for the test. I drove for another 300 miles and the sensors were still not reset for a test.

Where should I start?

Try adding a can of additive to the fuel tank, there are a few at places like autozone that are supposed to help, use it according to the direction, unless the check engine light is on the problem is that the monitors ran but did not complete, the computer o2 sensor monitors must run and show a pass, it's not completing the cycle, add the fuel treatment then drive it alternately at high speed and low speeds, accelerate/decelerate a few times, turn the key off and then repeat this a few more times, this may force the monitor to complete, other than that you can just try replacing the sensors and see what happens.  

Toyota Repair

All Answers

Answers by Expert:

Ask Experts


Ted Ritter


I have more than 28 years experience as toyota technician, I will be able to answer most questions related to the Toyota product line up to the present year models,I am located in the US but welcome questions from other regions of the world. When asking a question please provide specific information: year,model, engine,transmission information. Provide as much information as possible including a brief repair history if possible. I have been a volunteer here for more ten years an have answered over 16,000 questions helping Toyota owners with their problems and save thousands of dollars without any compensation, some of my answers are published on many other websites including google and various automotive forums. DONATIONS ARE VERY MUCH APPRECIATED, IF YOU HAVE RECIEVED HELPFUL INFORMATION PLEASE MAKE A DONATION. AS OF TODAY (JULY 22, 2014) ALL REQUESTED GRAPHICS, ILLUSTRATIONS, DIAGRAMS, PHOTOS, WILL REQUIRE THE MINUMUM DONATION UP FRONT.


Toyota technician since 1979,expert in electrical systems,OBD systems,engine repair, driveability problems,EFI systems,ASE certified,Toyota master technician.
Certified Hybrid Vehicle technician.

Toyota master technician, ASE certified in eight catagories, Hybrid vehicle certified. Toyota technical training: Engine Automatic transmission Manual transmission Drivetrain Electrical systems Brakes and chassis Air conditioning Engine performance and diagnostics Hybrid systems

©2016 All rights reserved.