P2098: Post-catalyst fuel trim system too lean (bank 2)

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.

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 this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

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 the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

• P2090 Camshaft actuator B control circuit low (bank 1)
• P2091 Camshaft actuator B control circuit high (bank 1)
• 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)
• P20B9 Reductant (AdBlue) heater A control circuit open or faulty
• P20E8 Reductant (AdBlue) pressure too low
• P20EE SCR NOx catalyst efficiency below threshold (bank 1)
• 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)

P2098 is a generic code, so it means the same on any make, for example on Abarth, Alfa Romeo, Cupra, Jeep, Nissan, Škoda. See what Final OBD does on your car in makes and models.