Problems with Opel Signum petrol engine 2008: Flashing engine light, loss of power and strong exhaust odor

Hello, I had a similar problem with my Opel Vectra, built in 2006. I have some experience with cars, but I let the professionals at the garage do something like this. It turned out that the engine control unit was defective. That cost me about 1000.0 euros to fix. Could you give me a few more details about your car? Mileage, transmission type, etc. might be helpful to help you better.

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Hi, thanks for your quick reply. My Signum has already done quite a bit, exactly 179453 kilometers. The last time I was in the garage was about 7 months ago. Your assumption about the engine control unit could be correct. I'll definitely visit a garage. A thousand euros is a lot of money, but safety first. Thanks again!

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No problem, you're welcome! Yes, your Signum definitely has quite a few kilometers on the clock. So it makes sense to have it checked thoroughly. At best, it's something minor and not as big an item as the engine control unit, but you'll probably have to visit a garage to find out. I'll keep my fingers crossed that it's nothing serious and that the costs are limited. Safety comes first in any case, I agree. Keep us up to date, I'm looking forward to seeing what comes out of the examination. All the best!

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Sure, thanks for your support! As soon as I know anything new, I'll let you know. Until then, I wish you all the best and thanks again for your help. Bye!

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Getting a misfire report and a cylinder 4 misfire report for a 2007 Opel vectra. Fault p0304 and p0300 I changed the plug in cylinder 4 and no difference so I changed the ignition coils (all 4 are connected) and still the same issue. Was overheating also but that appears to have stopped but still drives sluggish and struggles to start and same codes keep coming up even after clearing the faults. Any suggestions?

Check for any vacuum leaks, as they can cause misfires and rough idling. Inspect the intake manifold, hoses, and connections for any signs of damage or disconnection. Let me know if you find anything unusual or if you have further questions!

Thank you for your advice. Can you help me with some way of knowing where to find these items on the engine as the owners manual has gone missing and I’m not sure where to be looking. Also could it be fuel injectors possibly? I’m not sure where they are located on this car. Thanking you in advance

Start by checking the intake manifold, which is typically located on the top or side of the engine. Look for any hoses or connections leading to it and inspect them for cracks or disconnections. As for the fuel injectors, they are usually mounted on the engine's intake manifold or cylinder head. If you suspect the injectors, consider using a fuel injector cleaner or having them professionally tested. Let me know how it goes or if you have more questions!