P2194 — Engine running too rich under heavy load on bank 2

The engine is getting too much fuel compared to air on the second bank when under heavy load. This usually happens because the oxygen sensor detects excessive fuel, causing the computer to flag a rich condition. It can lead to poor fuel economy, increased emissions, and potential engine damage if ignored.

Common causes

The cause is almost always one of a few things. Here they are — P2194 rarely comes from anything outside this list:

• Faulty oxygen sensor on bank 2
• Leaking or stuck fuel injector on bank 2
• Vacuum leaks or intake leaks near bank 2
• Faulty fuel pressure regulator causing high fuel pressure
• Exhaust leaks affecting oxygen sensor readings

Where to start

In the order a sensible mechanic would work — the cheap checks first, the expensive replacements only after:

1. Check for vacuum or intake leaks around bank 2
2. Test and clean or replace oxygen sensor bank 2
3. Inspect and test fuel injectors on bank 2
4. Check fuel pressure and regulator function
5. Replace faulty fuel injectors or sensors as needed

That is what holds for P2194 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.