GTR Check Engine Light Power Loss

I also own a GTR, and I had similar symptoms a while back. Reduced power, check engine light… It could be a crankcase issue. Have you checked for any unusual idle or any signs of a leak around the ventilation system?

Thanks for the quick reply! I haven't checked for leaks specifically. Where exactly should I be looking around the ventilation system? And what do you mean by 'unusual idle'?

By unusual idle, I mean if it fluctuates erratically. If you're not familiar with the system, it's best to have a workshop take a look. A defective crankcase ventilation can cause all the issues you're describing. It's worth getting diagnosed properly to avoid further damage. In my case, replacing the valve was essential.

Okay, I understand. I'll take it to a workshop to get it checked out. Thanks for sharing your experience and the advice! Turns out you were spot on. Replaced the crankcase ventilation, cost me 360€, and all issues are gone.