P2099: Post Catalyst Fuel Trim System Too Rich — Bank 2
What to do
As P2097 — and the one-bank-or-both question again, because it is the cheapest piece of evidence available.
What this code means
Bank 2's downstream fine-trim has hit its rich limit — P2097's suspect list on the other bank, and P2098's bank-comparison rule in mirror: both banks rich says shared fuelling (pressure, a regulator), one bank alone says that bank's injectors, sensor or oil. The last of the P20xx block's decimal-numbered slots; the block runs on through its hexadecimal ones to P20FF.
Likely causes
Start here
- Aged or lazy downstream oxygen sensor · moderate
Less common
- Leaking fuel injector · moderate
- Excessive fuel pressure · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P2099.