P2180: System Too Rich Off Idle (Bank 2)

P2180 closes the series: bank 2's long-term trim must remove too much fuel above idle, so its multiplicative adaptation sits at the rich limit. GM's 2005 2.8 and 3.6 V6 and the 2008 3.6 LLT use a factor below 0.78, GM's 2024 tables below 0.77, both over two trips. VW's 2014 Touareg 3.0 TSI hybrid and 3.6 VR6 set it below -30 % on bank 2. Unlike P2190, which reacts to excess fuel at idle such as purge vapour, this code rises with load, so look at fuel delivered per injection: pressure regulator or high-pressure pump control, injectors leaking or over-delivering on bank 2, or a bank 2 front sensor reading rich. When P2178 is set as well, check the air mass reading and fuel pressure first. No bulletin naming this code was found.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

• Check engine lamp on after two trips
• Higher fuel consumption

Most likely causes

• Injector on bank 2 leaking or over-delivering
• Fuel pressure too high or air mass sensor over-reading, usually with P2178
• Bank 2 front oxygen sensor reading rich

What to check, in order

Start with the simplest. You can tick off each step.

1. Check short-term and long-term fuel trims in live data
2. Look for air leaks at hoses and gaskets
3. Check the mass air flow sensor (MAF) and, if appropriate, clean it with a dedicated cleaner
4. Measure the fuel pressure
5. Check the injectors and the oxygen sensor

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P2180 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 1: Air and fuel
• 80: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2180?

You can drive in moderation for a short time. A very lean or very rich mixture can damage the engine or the catalytic converter.

What causes code P2180?

The most common causes are: injector on bank 2 leaking or over-delivering; fuel pressure too high or air mass sensor over-reading, usually with P2178; bank 2 front oxygen sensor reading rich.

Related codes

• P2178System Too Rich Off Idle (Bank 1)
• P2179System Too Lean Off Idle (Bank 2)
• P2190System Too Rich at Idle (Bank 2)
• P0175System Too Rich Bank 2

Sources

• gsi.ext.gm.com: 2005file14
• gsi.ext.gm.com: 08 GRP02 LLT Engine
• gsi.ext.gm.com: 24OBDG07
• static.nhtsa.gov: MC 10074008 2280

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.