Seat Tarraco Diesel Issues

Sounds like a classic MAF sensor issue! I had similar symptoms on my old Volvo – performance decline, rough idle, the whole shebang. Did you check your air filter? A clogged air filter can sometimes contribute to MAF sensor problems by messing with the air intake and throwing off the air-fuel ratio. Has the check engine light come on?

Interesting! I did not check the air filter, but I'll take a look. When you say 'messing with the air intake', could you elaborate a bit more on what you mean? And yes, the check engine light is indeed illuminated.

Okay, so the check engine light confirms it even more. By 'messing with the air intake', I mean that if the air filter is blocked, the engine has to work harder to pull air in. This can create a vacuum and affect the readings the MAF sensor is sending to the ECU, which in turn can cause all sorts of problems with the air-fuel ratio. Given all the symptoms, I would suggest taking it to a workshop to get the MAF sensor properly diagnosed. It might save you some headaches down the line.

I took the Tarraco to the workshop, and you were spot on. They confirmed the mass air flow sensor was defective. After replacing it, the car runs like new again. Fuel consumption is back to normal, no more stalling, and the check engine light is gone. Total cost was 365€, parts and labor included. Thanks a lot for your help!