We recommend following the Acura CL drive cycle below at least twice. If the catalyst monitor is still not ready, and the new oxygen sensor(s) you installed are not OEM parts, we'd recommend replacing them with the OEMs. Although the check engine light may have turned off after replacing the O2 sensor(s), the new sensor's operation may not be preciously what is needed to get the catalyst monitor to set. Using the OEM part will guarantee the sensor outputs correct values. We also recommend checking your Acura CL for any pending trouble codes. Is it possible the catalytic converter is marginally operational? A trouble code P0420 will indicate this. If absolutely no trouble codes are present continue with the drive cycle. Usually driving in both city and highway conditions over the course of a few days is enough to get the drive cycle to run and make the emission monitors ready (or complete) for the smog test. At times however, due to individual driving habits, following the Acura CL drive cycle is required.
How to Complete an Acura CL Drive Cycle
Performing the driving pattern below will allow your Acura to make ready all I/M emission monitors in preparation for a smog inspection. Follow the drive cycle carefully. Take extra caution when performing the drive cycle on public roadways. If you feel you will be unable to follow the Acura drive cycle safely, please seek assistance from an smog check repair station or Acura dealership. They may be able to perform the drive cycle utilizing a dynamometer, and specialized scan tools. Prior to beginning the drive cycle ensure your vehicle has between 15% to 85% fuel in the gas tank, and that the engine is cold. It is best to start the driving cycle in the morning (after a cold soak).
All Monitor Drive Cycle - This drive trace is intended to make READY all the emission monitors listed below in one driving trace.
1) MIL (malfunction indicator lamp) must be off
2) Cold start (Best to start in the morning after the vehicle has sat overnight)
3) 1/4 to 3/4 fuel in gas tank. Ensure your Acura is not running empty or full of fuel.
1) Without depressing the accelerator pedal, start the engine and idle for 20 seconds.
2) Keep the transmission in Park. Increase the engine speed to 2,000 rpm and hold until engine temperature gauge rises to 1/4 of the scale. Approximately 3 minutes of idle time should accomplish this.
3) Begin driving. Increase speed to 50-60 mph as soon as safe and possible and maintain speed for at least 20 minutes. This step should be performed on the highway and with the transmission in Drive. Cruise control should not be enabled at any time.
4) Drive an additional 90 seconds without moving the accelerator pedal at all. Your vehicle speed may vary slightly, but no greater than 3 mph. If it is not possible to maintain steady speed for 90 seconds, drive for at least 30 seconds, then repeat 30 second steady speedy intervals, twice (for a total of 90 seconds). The goal is, at some point of highway driving, to not move the accelerator pedal for 90 seconds.
5) Exit highway and reduce speed to city/suburban traffic. Drive for at least 10 minutes.
6) When possible, allow vehicle to coast for 10 seconds without depressing the accelerator or brake pedal.
Drive Cycle Complete. Perform the drive cycle twice and using a scan tool check for emission monitor readiness.