Thanks in advance for any feedback. Replaced my battery about a month ago before going on a vacation. I did have to reset my radio and seat settings but didn't have any other issues. Had annual inspection today and failed the test because the evap system and 02 sensors monitors came back "not ready." The inspector guy told me to drive the car over the weekend and it should reset. I have only done some short city trips after the returning home -- and the car did sit for 10 days just after I replaced the battery. Wondering if anyone has any advice on the "drive cycle" needed to reset the monitors. Thanks!

2006 LS 430. 73K.

 

This is one way to prevent "cheating" to pass the emission test (not to imply that you are). As you know, you can clear DTC's by disconnecting the battery, and the car will take a while to get the DTC's back. Meanwhile if you take your car to an emission test, you will have no DTC's, but, your car will also show that the reason for no DTC may possibly because the sensors are not ready.

Here's a link to TxDPS that explains what is tested during the emission test: https://www.txdps.state.tx.us/rsd/vi...SystemsChecked

Attached is an article I found on the internet which explains the situation. I think the standard answer is to drive your car "normally" for 100 miles to get all the sensors back online.

 

Evap takes forever. I believe in Cali they allow only evap to not be ready. Park the car overnight and drive it.

 

Good info, I have to get tested soon.

 

In addition to mileage, the number of engine starts and stops needed to be "ready" is also programmed into the engine control modules. So, simply turning the engine "on" running it for a few minutes, then "off" for a few then "on", etc. logs into the DTC system. You also need "cold engine" starts since emissions are monitored cold as well.

 

It's just a matter of driving long enough for the system monitors to be in the ready state. I drove mine for 45 mins while running errands and all systems were readied for tests.

 

i've always used the ford drive cycle to get the emissions sensors ready
http://www.obdii.com/drivecycleford.html

 

Forget the Ford drive cycles. Here are the Lexus drive cycles - the fastest way to set all 4 OBD-2 readiness monitors in all 2002 and higher Lexus vehicles (excluding 1MZ-FE engines ie. ES300 and RX300):

It is not essential to plug in Techstream or any other code reader, but doing so will tell you exactly when the monitors have completed, and will tell you the exact Intake Air and Engine Coolant temperatures, which helps with setting the #3 (Catalyst) and #6 (EVAP) monitors.

3) OBD Drive Pattern Number 3 (Catalyst Monitor - O2 Sensor Type)
Precondition: Ensure MIL is OFF, Engine Coolant Temp is 176F (80C) or greater, Intake Air Temp is 14F (-10C) or greater. If Intake Air Temp is less than 14F (-10C), repeat the drive pattern after cycling the ignition off.
3a) If Intake Air Temp was less than 50F (10C) when the engine was started, drive the vehicle at 40-55mph (64-88km/h) for 7 minutes. If Intake Air Temp was greater than 50F (10C) when the engine was started, drive for 3 minutes.
3b) Drive the vehicle at 35-45mph (56-72km/h) for approximately 7 minutes.
3c) If readiness status does not switch to "complete", ensure preconditions are met, turn ignition off, then repeat steps "a" through "b".
NOTE: Drive with smooth throttle operation, avoid sudden acceleration, avoid sudden deceleration as much as possible with the throttle fully closed.

6) OBD Drive Pattern Number 6 (EVAP Vacuum Pressure Monitor - Intrusive Type):
Precondition: Ensure MIL is OFF, fuel tank 1/2 - 3/4 full, altitude 7800ft (2400m) or less, both Intake Air Temp and Engine Coolant Temp between 40-95F (4.4-35C). If Intake Air Temp is less than 14F (-10C) or altitude is higher than 7800ft (2400m), the test can be completed by repeating all steps (including the cold soak) a second time after cycling the ignition off.
6a) Cold soak the engine - let the car sit ~8 hours or until the difference between Intake Air Temp and Engine Coolant Temp is less than 13F (7C).
6b) Remove and reinstall fuel tank cap to release pressure in the fuel tank.
6c) Start engine, engage A/C (to create a slight load), and idle until ECT is 167F (75C) or greater.
6d) Race engine at 3000rpm for 10 seconds
6e) Allow engine to idle with the A/C on for 15-50 minutes (note that it took less than 10 minutes on my 2002).

8) OBD Drive Pattern Number 8 (Front and Rear O2 Sensor System)
Precondition: Ensure MIL if OFF
8a) Start engine, idle for 2 minutes or more
8b) Drive the vehicle at 25mph (40km/h) or more for at least 50 seconds. Be sure engine speed remains above 900rpm.
8c) Stop the vehicle, allow engine to idle for 40 seconds or more
8d) Perform steps "b" and "c" ten times.
8e) If readiness status does not switch to "complete", ensure preconditions are met, turn ignition off, then repeat steps "a" through "d".

10) OBD Drive Pattern Number 10 (O2 Sensor Heater)
Precondition: Ensure MIL is off.
10a) Start engine, idle for 9 minutes
10b) Drive vehicle at 25mph (40km/h) or more for at least 2 minutes.
10c) If readiness status does not switch to "complete", ensure preconditions are met, turn ignition off, then repeat steps "a" through "b".

 

Thanks very much! I'm confused about "Precondition: Ensure MIL is off." Are you referring to Malfunction Indicator Light? And, with the engine off, the MIL would be off as well...?

 

The precondition means that before you start the process, the last time your engine was on, the MIL was off.

 

glad I found this post to reference w my new ‘18 pass smog!