As a car grows older, parts outreach their peak efficiency and should be replaced with new parts. Like the front O2 lambda precat sensor, which has an replacement interval of 250.000km, which my car already replaced sometime ago. Replaced it with a genuine Bosch OEM part. Noticed that my Long Term Fuel Trims (LTFT) were dropping, which is a good indicator.
Partnr: 0 258 007 137 / 0258007137