Post Catalyst Fuel Trim System Too Rich (Bank 2)

What it means

This code is the same as P2097 but on bank 2 of the engine. The engine computer has found that the oxygen sensor after the catalytic converter on this bank keeps reading rich, which usually points to a biased bank 2 upstream sensor or excess fuel in that bank's cylinders.

Related codes: P2097P2098P0175P0158P0430

Symptoms4

• Check engine light on.
• Higher fuel consumption.
• Fuel or sulfur smell from the exhaust.
• Failed emissions test.

Possible causes5

• Aged bank 2 upstream oxygen sensor with a biased reading.
• Bank 2 downstream oxygen sensor contaminated or stuck reading rich.
• One or more leaking injectors on bank 2.
• High fuel pressure or a stuck-open EVAP purge valve, usually with P2097 as well.
• Weak bank 2 catalytic converter (less common).

How to diagnose5

1. Read all stored codes; P2097 alongside it points to a shared cause such as fuel pressure or the purge valve.
2. Compare bank 2 sensor readings and fuel trims with bank 1 on a scan tool.
3. Measure fuel pressure and check that it holds after shutdown.
4. Check the bank 2 injectors for leaks.
5. Inspect the bank 2 downstream sensor for contamination deposits.

How to fix5

1. Replace the bank 2 upstream oxygen sensor if it is proven biased.
2. Replace a contaminated downstream sensor after fixing the source of contamination.
3. Repair or replace the leaking injector.
4. Replace the purge valve or pressure regulator if the cause is shared by both banks.
5. Clear the codes and confirm the trims return to normal.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for an oxygen sensor or purge valve, and rises when injectors are needed or the bank 2 sensors are hard to reach.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions