Powertrain, generic (extended)

P2190 System Too Rich at Idle (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2190 is the bank 2 counterpart of P2188: the long-term trim of bank 2 has to remove more fuel than allowed at idle and low load. GM's 2008 3.6 LLT sets it below -6.0 % in the same window it uses for P2188 (520 to 1120 rpm, 1.7 to 7.8 g/s, closed loop, coolant above 60 °C, catalyst heating not active), and GM's 2005 2.8 and 3.6 V6 treat it in the same additive adaptation range. A rich fault on bank 2 only usually lies in that bank: a leaking injector, or a bank 2 front sensor reading lean so the ECM keeps leaning the mixture. Fuel pressure, purge vapour and air-mass errors act on both banks and tend to set P2188 and P2190 together. Stellantis is an example: an airflow straightener clipped in wrong in the air box upset the air mass reading and logged P2188 and P2190 together, sometimes with P0111 and an unstable idle; refitting it correctly cured it.

Likely causes

Leaking injector on bank 2
Shared cause such as air mass error or purge vapour, usually with P2188 too
Bank 2 front sensor reading lean

Symptoms

  • Malfunction indicator lamp on
  • Rough idle, fuel smell

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–600
Time0.5–3 h

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

Parts involved

fuel injectoroxygen sensor upstreammass air flow sensorevap purge valve

Related codes

P2188P2189P0175P2180

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