Seat Tarraco Hybrid NOx Catalyst Issue

Whoa, that sounds eerily familiar. I had something similar happen with my Tarraco too, though it wasn't a hybrid. Check engine light flashing, and the car felt sluggish. Have you noticed any drop in your fuel efficiency? Did you run any car diagnostics yourself to pull the error code?

Fuel efficiency is hard to say, I haven't been paying close attention, but I'll keep an eye on it now. The error code was pointing towards the NOx catalyst aging. That's why I'm worried it's the catalytic converter itself. You mentioned your car felt sluggish. Was it the same error code? And did you end up replacing the whole catalytic converter?

Right, the sluggishness was definitely linked. And a leak in the exhaust system can definitely mess with the NOx catalyst readings, giving you that 'aging' error. I didn't replace the catalytic converter in the end. The leak was the culprit. Honestly, get the exhaust system checked before you jump to conclusions about the NOx catalyst. A garage should be able to pinpoint the leak pretty quickly.

Turns out you were spot on. Took it to the local garage after doing some car diagnostics myself and yup, exhaust was leaking. They replaced the faulty section, and the error's gone. Cost me 265€, which I'm happy to pay to get rid of that annoying engine light. Thanks a lot for your help.