Powertrain, generic (extended)

P2180 System Too Rich Off Idle (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

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

Symptoms

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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–900
Time0.5–3.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel injectorfuel pressure regulatoroxygen sensor upstreammass air flow sensor

Related codes

P2178P2179P2190P0175

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.