P0175

P0175 is the bank-2 'rich' code — too much fuel for the air entering bank 2, with LTFT pulled past -25% trying to lean things back out. Diagnosis collapses into the same logic as P0172 but isolated to one bank, which is actually useful because anything wrong upstream of both banks (global fuel pressure, contaminated MAF, failed canister purge venting into the common plenum) tends to throw P0172 and P0175 together — when only P0175 sets, the cause is mechanically scoped to bank 2. Cheapest checks first: clean the MAF with sensor-safe spray (P0175 alone from a MAF is rare but worth ruling out at $12), then pull and inspect the bank-2 spark plugs — soot-black, sooty deposits on every plug on that bank is direct confirmation the bank is running rich, and clean ceramic on bank 1 with sooty bank 2 plugs is the diagnostic photograph. Next, scope or noid-test the bank-2 injectors looking for one stuck open or with degraded pintle return — a single leaking injector dumps fuel continuously into one cylinder and drives the whole bank rich. Finally check the bank-2 upstream O2 sensor: a sensor with a slow switching response or stuck near 0.9V can fool the ECU into the wrong direction. Black smoke from the tailpipe at idle plus a strong gasoline smell at the bank-2 exhaust manifold is the field signature.

Vehicle-specific patterns: 2002-2008 Dodge Ram 1500 / Durango with the 4.7L V8 commonly throws P0175 from a leaking #6 or #8 injector (bank 2 on this engine) that sticks open at idle — Bosch makes the OEM injector and replacing it as a set on that bank is the durable fix. 2003-2007 Cadillac CTS / SRX with the 3.6L LY7 V6 throws P0175 from a failed evaporative-purge solenoid that vents fuel vapor into the bank-2 intake during cold operation. 2007-2013 GMC Acadia / Buick Enclave / Chevy Traverse with the 3.6L LLT direct-injection V6 throws P0175 from carbon-coked injectors on the bank-2 side — a chemical decarbon plus injector replacement is common around 100k miles. 2000-2006 Mercedes E320/CLK320/SLK320 with the M112 V6 throws P0175 from a failed bank-2 air-mass meter or stuck-open purge valve. Repair cost typically $50-$500 — MAF cleaning at the low end, injector replacement at the high end ($300-$500 for a single OEM injector + labor).