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1996 Chevrolet S-10 Check Engine Light: OBD2 Codes P0121, P0171, P0174 Explained

Model: 1996 S-10 Fault Code: P0121 Posted: 2015-08-20 12:32

I'm experiencing a check engine light on my 1996 Chevrolet S-10 with engine code readings showing P0121, P0171, and P0174. The vehicle has a 2.2L inline-four engine with catalytic converter. I've checked the OBD-II scanner and confirmed these codes are active. The P0121 code indicates an issue with the intake air temperature sensor, while P0171 and P0174 suggest lean mixtures in both fuel banks—P0174 specifically points to a lean condition on the second bank of the engine. I'm looking for troubleshooting steps and potential causes. Could this be related to faulty oxygen sensors or vacuum leaks? I've already ruled out major mechanical issues, but I'd like to confirm if these codes point to sensor failure or fuel delivery problems.

Related fault codes
P0121P0171P0174
Comments (4)
Anonymous 2015-08-20 13:01

Please specify your vehicle details: year, make, model, engine type (e.g., 2.2L 4-cylinder), and whether it has a catalytic converter. This helps narrow down potential causes for the P0121, P0171, and P0176 codes.

Anonymous 2015-11-06 22:47

Oxygen sensors are a common cause of P0171 and P0174. If one or both sensors are failing, they may not provide accurate feedback to the ECU, leading to incorrect fuel mixture adjustments and lean conditions.

Anonymous 2015-11-07 08:20

P0171 and P0174 both relate to lean air-fuel mixtures. According to OBD-II code database, P0174 specifically indicates a lean condition on the second fuel bank (second cylinder bank). These codes often occur together when one or more oxygen sensors are faulty or when there's a vacuum leak in the intake system.

Anonymous 2016-02-04 08:39

The issue is likely tied to the oxygen sensor(s) on my 1996 S-10 with a 2.2L engine and catalytic converter. I suspect one of the O2 sensors has degraded, especially given the P0171 and P0174 codes. A vacuum leak could also contribute, but I've checked for visible leaks and found none.