P2097 Mixture too rich after the catalytic converter

By: Diagno editorial team · Updated: 2026-10-15

P2097 means: Mixture too rich after the catalytic converter. According to the rear oxygen sensor, the mixture after the catalytic converter is wrong. OK to drive, but have it checked soon. The most common repair costs about €90–180 in Estonia, depending on make and model.

What it means

According to the rear oxygen sensor, the mixture after the catalytic converter is wrong. Often the sensor itself or an exhaust leak is to blame.

What could be wrong

1. 1Rear oxygen sensor is faulty · Oxygen sensor replacement €90–180
2. 2Exhaust leak · Leak check and hose or gasket replacement €60–120
3. 3Front oxygen sensor reads wrong · Oxygen sensor replacement €90–180
4. 4Catalytic converter is worn out · Catalytic converter replacement €450–900

What you can check yourself

Listen for an exhaust leak. Check the rear sensor wire. You can check the simple things yourself, but the repair is best done in a workshop.

How we fix it

1. We compare the readings of both oxygen sensors
2. We check for exhaust leaks
3. We replace the sensor or fix the leak

Standard SAE description: Post Catalyst Fuel Trim System Too Rich (Bank 1)