P2098: Post-catalyst fuel trim system too lean (bank 2)
The oxygen sensor after the catalyst on bank 2 sees too much air in the mixture and the ECU cannot correct it. Often a leak or the sensor.
| Code | P2098 |
|---|---|
| System | Engine and transmission |
| Group | P20xx, Emissions: catalysts and AdBlue |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P2098 means
The oxygen sensor after the catalytic converter (sensor 2) also helps fine tune the fuel mixture. This code means that on bank 2 it sees a lean mixture, with too much air, and the ECU has reached the limit of what it can correct. It is usually caused by air getting into the exhaust or an ageing sensor.
Most common causes
- An exhaust leak ahead of the rear sensor (gasket, flange or rusted pipe)
- The downstream oxygen sensor old or slow to respond
- Damaged wiring or connector on that sensor
- An intake air leak or a split vacuum hose
- Low fuel pressure or dirty injectors
- A worn catalytic converter
Symptoms
- Engine warning light on
- Often nothing noticeable while driving
- Occasional hesitation or a slightly unstable idle
- May fail the emissions test at inspection
Can you drive with P2098?
With care You can drive, but running lean for a long time can overheat the engine and the catalyst. Have it looked at soon.
Open the bonnetthe in-depth explanation
How to check it
Use a live data reader to watch the bank 2 sensor 2 voltage: if it stays low most of the time, the mixture is lean or there is a leak. On a cold engine, a puffing or ticking noise from the exhaust points to a leak.
How to read and clear P2098 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2098 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2094 The camshaft actuator B circuit on bank 2 has a low signal
- P2095 The camshaft actuator B circuit on bank 2 has a high signal
- P2096 Post-catalyst fuel trim system too lean (bank 1)
- P2097 Post-catalyst fuel trim system too rich (bank 1)
- P2099 Post-catalyst fuel trim system too rich (bank 2)
- P209A The AdBlue injection air pressure sensor B has an electrical fault
- P209B The AdBlue injection air pressure sensor B gives readings outside the normal
- P209C The AdBlue injection air pressure sensor B gives a lower signal than normal
- P2002 Diesel particulate filter efficiency below threshold (bank 1)
- P2003 Diesel particulate filter efficiency below threshold (bank 2)
- P2004 Intake manifold runner control stuck open (bank 1)
- P2005 Intake manifold runner control stuck open (bank 2)
What does code P2098 mean?
The oxygen sensor after the catalytic converter (sensor 2) also helps fine tune the fuel mixture. This code means that on bank 2 it sees a lean mixture, with too much air, and the ECU has reached the limit of what it can correct. It is usually caused by air getting into the exhaust or an ageing sensor.
Can you drive with P2098?
You can drive, but running lean for a long time can overheat the engine and the catalyst. Have it looked at soon.
How do you clear P2098?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2098 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
