System Too Rich at Idle Bank 1

The engine is running too rich (too much fuel, not enough air) when idling on the cylinder #1 side of the engine, harming fuel economy and causing rough idle. This is usually caused by a faulty fuel pressure regulator, leaking fuel injector, or faulty oxygen sensor. The driver may notice black smoke from the exhaust and poor fuel economy.

No detailed repair guide linked yet. Check back soon or search for related issues.