Rob Mc Posted December 21, 2025 Report Posted December 21, 2025 I have had my 2008 R56 mini tuned for years. Also have a Milltek high flow cat and a jspacer on the downstream O2 (among other mods) . When it comes time for emission in MD I typically clear any codes, complete a full drive cycle (idle, targeted speeds/rpm and sleep as outlined below) then go to emissions before any new codes are thrown. This time my O2 and Evap tests are not ready - after several drive cycles and 200+ regular miles. I am about to throw money at the problem - new upstream O2, new battery (current one is 5+ years old) But thought I would hit pause and see if any of you good people have encountered this issue and have any suggestions The drive cycle requires a mix of city and highway driving under specific conditions. It may need to be repeated a few times to set all monitors, especially the EVAP system. Cold Start & Idle: Start the engine and let it idle for 2 to 3 minutes with all accessories (A/C, headlights, defroster) off. This allows the O2 sensor heaters and other initial systems to be tested. City Driving (Low Speed): Accelerate gently and drive at a steady speed of 20-30 mph for about 3 minutes and 15 seconds. Avoid heavy acceleration or braking. Highway Driving (Steady Speed): Accelerate to and maintain a steady speed between 40-60 mph for about 15 minutes. Using cruise control on a safe, open stretch of road can help maintain a consistent throttle position, which is crucial for the catalyst monitor test. Deceleration (Coasting): Without using the brakes, release the accelerator pedal and coast down to about 20 mph. Repeat this step a few times. Stop & Idle: Bring the vehicle to a complete stop and let it idle for at least 2 minutes. Do not roll through stops. Engine Off/Door Open: Turn the car off, open the driver's door, and close it. Waiting a few minutes allows the car's computer to fully power down and "finalize" the drive cycle data.
BMINIW Posted December 31, 2025 Report Posted December 31, 2025 Hi on my stock '03 R50, I couldn't get the P2097 code to clear despite new Bosch O2 sensors and after what I considered double the necessary drive cycle. Turns out one of the brand new Bosch sensors was bad and replacing it soon cleared the codes.
Rob Mc Posted December 31, 2025 Author Report Posted December 31, 2025 If I had any codes I could at least chase the problem. In my case I don't have any codes and my O2 and Evap won't show ready despite several hundred miles and a few attempts at the drive cycle noted in my original post. I have be over to the tuner who kindly put the tune back to stock no charge, purchased a new battery (6 years old - just incase power was below minimum when car was off) and now am about to replace the upstream O2 (long shot w no code showing) and fuel filter w new seal - first replacment in 18 years (long shot incase there is a slight leak on Evap but enough to throw code). ANY other ideas - Please and Thank you. Happy New Year
