AFN Performance Issues: Troubleshooting & Fixes

Hello,

I'm having a problem with my Toledo AFN. When driving, there's a slight jerk, and the car continues to run normally until I try to accelerate, at which point it loses power. After restarting the engine, the power is restored. The problem isn't constant; it's occurred 4 times in the last 4 months. After the first occurrence, the workshop replaced the mass airflow sensor (MAF), and everything was fine for about a month, but it happened twice yesterday. I've read in forums that it might be a limp mode issue, but I'm not sure what's triggering it. I can't read any diagnostic data because I don't have the necessary equipment. I'm not expecting a definitive diagnosis, but I would appreciate any tips so I can be somewhat prepared when I take it to the workshop.

Thanks in advance,
Volker

'I once had a similar issue. I was messing around with something and forgot to reconnect the vacuum line to the control unit during reassembly. This resulted in the exact effect you described: the emergency mode would engage under increasing load. Everything was fine in gears 1-4 with full throttle, but starting at 120 km/h in 5th gear, the emergency mode would kick in.'

Perhaps one of the rubber seals is pushed in or porous. I would check that first.