P2190

P2190 sets when bank 1 runs RICH specifically AT IDLE — STFT + LTFT pinned below -10% (and often near -25%) at warm idle while the same trims clean up to ±5% at cruise. The idle-only signature points hard at causes that dump fuel only when intake airflow is low: a slowly leaking injector pintle that drips between firing events (overwhelming the small idle airflow), an EVAP purge valve stuck open at idle venting raw fuel vapor from a saturated canister into the intake, a fuel-pressure regulator with a torn diaphragm siphoning liquid fuel through the vacuum reference line, or a coked / sticky direct-injection intake valve that holds extra fuel film. Cheapest-first ladder: pull the bank-1 spark plugs and inspect — uniformly sooty black across all bank-1 plugs is direct visual confirmation of a rich bank. Clear the EVAP purge valve from the diagnostic by unplugging it and seeing if the rich condition disappears in 60 seconds (key-on, engine-running, scan tool). Pull the vacuum reference line from the fuel-pressure regulator (port-injection only) and look for liquid fuel — torn diaphragm if present. Scope or noid-test bank-1 injectors looking for one slow to close. The at-idle code is the giveaway — leaky injector seat or coked intake valve (on direct-injection engines) for rich; don't condemn the O2 sensor, it's reporting what it sees.

Vehicle-specific patterns: 2002-2008 BMW N42/N46/N52 (3-series, 5-series) commonly throws P2190 from a stuck-open canister purge solenoid that leaks fuel vapor into the bank 1 intake at idle — $60 valve, 30-min fix. 2007-2014 GM 3.6L LFX/LLT direct-injection V6 (Camaro, CTS, Acadia, Traverse) throws P2190 from carbon-coked intake valves and from sticking high-pressure fuel pump check valves that allow rail bleed-down into the manifold at idle — walnut-blast decarbon plus HPFP service is the durable repair around 100k miles. 2005-2010 Dodge Charger / 300 / Magnum 5.7L Hemi throws P2190 from a leaking #1 or #3 injector pintle that drips into the bank-1 cylinders on hot soak — Mopar TSB coverage for Bosch injector replacement on certain build dates. 2003-2009 Toyota 4Runner / Tundra 4.7L 2UZ-FE throws P2190 from a saturated EVAP canister after a gas-station overfill venting raw fuel vapor through the purge solenoid into the bank-1 intake. Estimated repair: $60 to $750.