Facing a smog check failure because your car’s OBD2 monitors aren’t ready can be frustrating. Many car owners encounter this issue, often seeing messages like “Catalyst not ready” or “Evap system not ready” on their smog inspection report. If you’re in this situation, understanding why this happens and what you can do about it is key to passing your smog test and getting back on the road legally.
One potential solution to reset these monitors to a “ready” status is to perform a drive cycle. A drive cycle is a specific series of driving conditions that your car needs to complete to run self-tests on its emission control systems. These tests ensure that components like your catalytic converter and evaporative emissions system are functioning correctly.
For instance, a Toyota MR2 with a 2AZ-FE engine might require a drive cycle like this:
- Start your car and let it idle for at least 10 minutes.
- Drive at a steady speed between 43-56 mph for 3 to 5 minutes, keeping the engine speed between 900 and 3,200 rpm.
- Stop and idle for another 3 to 5 minutes.
- Repeat the previous two steps once more.
- Drive at 40-55 mph for 3 minutes.
- Drive at 35-45 mph for 7 minutes.
- Stop, turn off the engine, and briefly release fuel tank pressure by removing and reinstalling the gas cap.
- Restart and drive at around 45 mph for 5 minutes.
- Drive at approximately 25 mph for 15 minutes, including at least two 30-second stops.
- Stop and idle for 2 minutes.
- Drive at 25 mph or more for at least 50 seconds, ensuring engine speed stays above 900 rpm.
- Stop and idle for 40 seconds or more.
- Repeat the last two steps ten times.
It’s crucial to remember that drive cycles are vehicle-specific. This example is for a Toyota MR2 with a specific engine. Your car might need a different procedure. Consult your vehicle’s repair manual or search online for the correct drive cycle for your make, model, and year.
If, after completing the appropriate drive cycle, your OBD2 monitors still show as “not ready,” there could be underlying issues preventing them from completing. In such cases, using an OBD2 scanner can be beneficial. These scanners, like the Autel MS309, allow you to check your car’s readiness status yourself. They can confirm if the monitors have reset or if there are any trouble codes that are hindering the process.
While a drive cycle can often resolve the “not ready” issue, especially after recent car repairs or battery changes, it’s not a guaranteed fix. If you continue to fail smog checks due to OBD2 monitor readiness, it’s advisable to seek professional help from a qualified mechanic. They can diagnose any potential problems with your emission system and ensure your vehicle is ready to pass the smog test.
