P2098 2015 GMC Sierra Code - Post Catalyst Fuel Trim System Low Limit Bank 2

P2098 indicates that the post-catalyst (downstream) oxygen sensor on Bank 2 has detected a lean condition, meaning the air-fuel mixture is too lean after passing through the catalytic converter.

Common symptoms include the check engine light turning on, reduced fuel efficiency, poor engine performance, and, in some cases, a noticeable exhaust odor.

Possible causes include a faulty downstream oxygen sensor, exhaust leaks, a malfunctioning catalytic converter, vacuum leaks, or issues with the fuel system such as low fuel pressure.

Start by inspecting the exhaust system for leaks, checking the downstream oxygen sensor for damage, and verifying proper fuel pressure. Use a scan tool to monitor oxygen sensor readings and perform a smoke test for vacuum leaks if necessary.

Yes, a defective downstream oxygen sensor on Bank 2 is a common cause of the P2098 code, as it may send incorrect signals to the engine control module (ECM).

Bank 2 refers to the side of the engine that does not contain cylinder #1. On a V8 engine, this is typically the passenger side.

While the vehicle may still be drivable, ignoring this code can lead to reduced engine performance, increased emissions, and potential damage to the catalytic converter over time.

Repairs may involve replacing the downstream oxygen sensor, fixing exhaust or vacuum leaks, addressing fuel delivery issues, or replacing the catalytic converter if it's damaged.

Yes, poor-quality or contaminated fuel can cause an improper air-fuel mixture, potentially triggering the P2098 code.

The repair cost depends on the root cause. Replacing an oxygen sensor typically costs $150–$300, while fixing exhaust leaks or replacing a catalytic converter can cost significantly more.