Powertrain, generic (extended)

P2197 O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2197 is the bank 2 version of P2195 on engines with a front sensor per bank: the bank 2 front oxygen or A/F sensor keeps reporting lean in a way the ECM rejects. GM's Bosch-based 2005 2.8 and 3.6 V6 flag it when the bank 2 rear sensor reads rich (above 0.85 V) while the front sensor reads leaner than lambda 1.08 with short-term trim at its 1.25 maximum, a contradiction a real lean mixture would not produce. Ford applies its switching, trim-limit and, from 2019, stuck-lambda tests to bank 2 the same way, with a 30 s window. Ford's 2017 bulletin for 2015 to 2017 Explorer and 2015 to 2016 F-150 3.5 GTDI lists P2195 and P2197 with P2626 and P2629, the pumping-current trim circuits of the A/F sensors, and fixes them with new heated oxygen sensors. If only bank 2 is affected, an exhaust manifold leak on that side ahead of the sensor is worth ruling out before replacing the sensor.

Likely causes

Bank 2 front oxygen or A/F sensor aged or contaminated
Exhaust manifold leak on bank 2 ahead of the sensor

Symptoms

  • Malfunction indicator lamp on
  • Possible rough running or higher consumption

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–300
Time0.3–1.5 h

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

Parts involved

oxygen sensor upstreamoxygen sensor wiringexhaust manifold

Related codes

P2195P2198P0151P0174P2629

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