Lacetti Check Engine Light Sluggish Performance

The symptoms you describe are concerning. Have you checked for any specific error codes using an OBDII scanner? Such a combination of issues can arise from a faulty crankshaft sensor affecting engine synchronization. I encountered a similar problem on my old Opel Astra; it turned out to be a defective camshaft sensor throwing off the timing, resulting in misfires and reduced performance.

Thanks for the input. You mentioned a camshaft sensor on your Astra. If the crankshaft sensor is faulty, would that also trigger issues with the camshaft timing? Are the two sensors related?

Indeed, the crankshaft and camshaft sensors work in tandem to provide the engine control unit (ECU) with precise data about the position of the crankshaft and camshaft. A discrepancy between these signals – a crankshaft to camshaft reference value issue – can cause the ECU to misinterpret the engine's timing, leading to the symptoms you're experiencing. Given the complexity and potential for further damage, a professional diagnosis at a workshop might be prudent.

Thanks a lot! I appreciate the detailed explanation. I took it to the workshop; you were spot on. It was the crankshaft sensor. Cost me 340€ to get it sorted, but at least the engine light is gone, and the car is running smoothly again.