Having replaced the battery on your Toyota MR2 caused it's emission monitors (also known as readiness flag) to erase. Emission monitors are internal self-tests which the engine control computer (ECU) performs in order to verify specific emissions systems, such as the EGR system, EVAP system, oxygen sensors and Catalyst, are functioning properly. If any one monitor is incomplete, not including the EVAP monitor, your MR2 can not pass the smog test. The EVAP monitor is the only monitor allowed to remain incomplete and the vehicle still pass the smog check because of the difficulty of getting this particular monitor to complete; though the State of California does intend to remove this exemption in the near future. In order to make the monitors ready for the smog check you'll need to drive your MR2 through what is known as a Drive Cycle.
Usually driving 200-300 miles over the course of a few days and in both city and highway traffic conditions is enough to get the drive cycle complete. Due to individual vehicle owner driving patterns however, sometimes the criteria required to get a particular monitor to initiate and/or become ready is not met. In such instances, it is required that a specific drive cycle pattern which is designed for the Toyota MR2, be followed.
How To Get Your Toyota MR2 Emission Monitors Ready for the Smog Check
Notice: Take extra caution when performing the drive cycle on public roadways. This particular drive cycle is very complex and requires many stops, starts and slow downs. It is best performed on a dynamometer. Perform the drive cycle at your own risk. If you feel you may be unable to perform the drive cycle below safely, please seek assistance from a reputable smog check repair station or Toyota dealership. A smog repair certified center will be able to perform the drive cycle on a dynamometer, eliminating the need to drive your car on streets and freeways.
Preconditions: (Make sure you have between 1/4 and 3/4 fuel in the gas tank. The EVAP test will not run while your Toyota MR2 has a full tank of gas or the gas tank is near empty). Ensure there are no pending or active trouble codes and that the check engine light is not on. Begin the drive cycle from a cold-start; having allowed your vehicle to sit overnight. Note, the secondary air injection monitor will require a cold-start in order to initiate.
Toyota MR2 Drive Cycle(Engine Class 2AZ-FE)
A. Start the engine and allow it to idle for 10 minutes or more.
B. Drive the vehicle at 43-56 mph or more for 3 to 5 minutes. Be sure to maintain engine speed between 900 and 3,200 rpm.
C. Stop the vehicle and allow the engine to idle for 3 to 5 minutes.
D. Repeat steps B and C once.
E. Drive the vehicle at 40 mph to 55 mph for 3 minutes.
F. Drive the vehicle 35 mph to 45 mph for 7 minutes.
G. Stop the vehicle and turn off the engine. Release the pressure in the fuel tank by removing and then reinstalling the fuel tank cap.
H. Start the engine and as soon as safely possible begin driving at approximately 45 mph for 5 minutes.
I. Drive the vehicle at approximately 25 mph for 15 minutes, and include a minimum of two stops for approximately 30 seconds each.
J. Stop the vehicle and allow the engine to idle for 2 minutes.
K. Drive the vehicle at 25 mph or more for at least 50 seconds. Make sure your engine speed is above 900 rpm.
L. Stop the vehicle and allow the engine to idle for 40 seconds or more.
M. Perform steps “K” and “L” ten times.
If readiness status of all monitors do not switch to “complete,” ensure preconditions are met, turn the ignition switch OFF, then repeat steps “A” through “M.”
