Audi S5 System Alert: OBD Readiness Issues Decoded

Having some experience with Audis, I encountered a similar situation with my 2020 Audi S4, which shares many components with your S5. The check engine light and system readiness issues often appear after disconnecting the battery or clearing fault codes. The onboard diagnostics system needs to complete several drive cycles to reset all monitors and establish proper system readiness. Before paying for repairs, try this: Drive normally for about 20-30 minutes, Include both city and highway speeds, Let the engine reach normal operating temperature, Perform gentle acceleration and braking In my case, the vehicle inspection showed all systems returned to normal after completing these drive cycles. The workshop confirmed via OBD2 diagnostics that no actual repairs were needed. To help provide more specific guidance: Have you recently had battery work done? Were any codes cleared recently? Which specific error messages are you seeing? Does the engine performance feel normal? Would be helpful to know these details to determine if your situation matches what I experienced.

Thanks for the detailed response. My mileage is at 160486 KM and I had no recent battery work done. The check engine light appeared suddenly during normal driving. The car still runs smoothly with no noticeable performance issues. The error messages specifically point to the exhaust system. The computer diagnostic shows incomplete readiness status in the emissions test parameters. I have tried the suggested drive cycle pattern but the check engine light persists after several attempts. Worried this might be more than just a computer reset situation. No battery disconnect or code clearing was done before these errors appeared. Wondering if I should still try more drive cycles or head straight to service.

Based on the mileage and symptoms you described, this differs from my initial experience. While my S4 issue was related to a computer reset, your case showing persistent exhaust-related codes despite multiple drive cycles suggests a potential hardware issue. At around 160000 KM on my S4, I encountered similar exhaust-related warnings. The car diagnostics revealed a failing oxygen sensor, which triggered both the check engine light and incomplete emissions test readiness status. The drive cycle method works for computer reset scenarios but wont resolve actual sensor failures. In my case, the repair involved: Complete system diagnostics (120 Euro), Oxygen sensor replacement (380 Euro), Computer reset and readiness verification (included) Since your error persists without any prior battery or computer work, and specifically relates to the exhaust system, I recommend getting it checked. These symptoms typically indicate sensor degradation, which is common at this mileage. The good news is your smooth running engine suggests the issue is likely isolated to monitoring systems rather than major mechanical problems. A proper diagnostic scan will pinpoint whether its the oxygen sensor, exhaust pressure sensor, or other emissions components.

Thanks for the input. After reading your responses, I'm going to take it in for service since this seems different from a simple computer reset situation. The consistent exhaust system errors and failed readiness tests, despite multiple drive cycles, point to actual hardware issues. My gut feeling was right about this being more than just an OBD readiness problem, especially since there was no battery work or code clearing before the check engine light appeared. The fact that similar symptoms on other S4/S5 models led to sensor replacements at comparable mileage makes me think Im dealing with the same issue. Will update once I get the vehicle inspection results and know the actual repair costs. At least the engine running smoothly gives me hope its just a sensor problem and not something more serious in the exhaust system.