VW Scirocco Error Codes: Check Engine Light Mystery

Based on my experience with a 2006 VW Golf GTI, which had similar onboard diagnostics issues, I can share some relevant insights. Having some experience with car diagnostics, I connected my OBD scanner and discovered that after a battery replacement, the readiness monitors needed time to complete their self-tests. This is quite common in VAG vehicles from that era. The car diagnostics showed several pending codes initially, but they cleared up after driving the car through a complete warm-up cycle. The check engine light turned off after about 50-60 kilometers of normal driving. The exhaust system monitors were the last to complete their checks. For proper diagnosis, could you share: How long has the check engine light been on? Did you recently have any work done on the car? What specific error messages are you seeing in the display? Do you have access to an OBD scanner to read the actual codes? In my case, the fix cost 0€ since it just required driving the car to complete all monitoring cycles. Most OBD readiness issues after battery disconnection or computer resets resolve themselves this way. Before your inspection, make sure all readiness monitors are complete, as incomplete monitors might cause you to fail the test.

Just completed my latest service at 123701km, but sadly these issues started right after. I borrowed an OBD scanner and it shows P0420 and P0011 codes. The check engine light has been on for about 3 days now. No battery work was done, but they did clear the computer during service. The speedometer display shows Check Engine and EPC warnings periodically. The car still drives fine but feels slightly rougher at idle. The drive cycle attempts so far havent cleared the codes. Getting worried about passing the emissions test next month with these ongoing issues.

Thanks for those details about the P0420 and P0011 codes. On my Scirocco, I faced almost identical issues after a service, same codes and symptoms. The P0420 typically points to catalyst system efficiency below threshold, while P0011 relates to camshaft timing. In my case, the rough idle and EPC warning stemmed from the camshaft timing issue, which affected the exhaust system performance. After several unsuccessful drive cycles, I discovered the root cause was two-fold: A failing catalytic converter (explaining the P0420), A dirty oil control valve affecting camshaft timing (P0011) The OBD readiness monitors wouldn't complete because these underlying issues needed fixing first. Simply clearing codes and running drive cycles won't resolve genuine mechanical problems. My repair costs were: Catalytic converter: 800€, Oil control valve replacement: 200€, Labor: 300€ For your emissions test success, I'd recommend addressing these issues soon. The catalyst problem especially will cause a definite test failure regardless of system readiness status. Would you like more specifics about the repair process or diagnostic steps I went through?

Thanks for sharing those details. Your situation definitely sounds similar to what other Scirocco owners experienced. The P0420 and P0011 combination makes sense given my symptoms. I realize now that just trying drive cycles probably won't fix the underlying issues. These fault codes appearing right after service suggests real mechanical problems rather than just computer reset effects. From your experience, I should budget around 1300€ for the complete fix including the catalytic converter and oil control valve. That's higher than I hoped, but better to address it now than fail the emissions test next month. Could you provide more specific information about the repair process and diagnostic steps? I'd like to understand what I'm dealing with before taking it to the shop. I'm particularly interested in whether any additional system readiness tests were needed after the repairs were completed.