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P2271 Diagnostic Trouble Code for 2012 Buick Regal 2.4L Engine: Causes and Solutions

Model: Buick Regal Fault Code: P2271 Posted: 2024-02-22 10:54

Hello everyone, I'm currently troubleshooting a persistent P2271 diagnostic trouble code on my 2012 Buick Regal with the 2.4L engine. Despite replacing both oxygen sensors multiple times, the code continues to return—preventing me from passing smog inspection. I've already checked the fuel injectors, wiring harnesses, and exhaust system for leaks, all of which appear intact. The issue persists even after thorough diagnostics. I'm seeking advice on what could be causing this recurring P2271 code. Could it be related to a faulty sensor, an electrical connection issue, or a deeper fuel system problem? Any insights from owners or technicians who have encountered this specific code on the 2012 Buick Regal would be greatly appreciated.

Related fault codes
P2271
Comments (4)
Anonymous 2024-02-23 15:59

Could you please share the engine live data and freeze frame information when the P2271 code is triggered? This will help identify whether the issue lies in sensor readings or system behavior.

Anonymous 2024-02-24 11:21

Here are some photos of the vehicle's components for reference.

Anonymous 2024-02-24 11:33

Upon inspecting the wiring and connectors, I found a crack in the fuel pressure pump connector with exposed wires. Could this damaged connection be causing intermittent signals that trigger the P2271 code? I've attached a photo showing the damage.

Anonymous 2024-03-02 12:01

The fuel system remains in open loop after approximately 10 minutes of idle, with ECT reading at 171°F. This may indicate an engine running too rich, which could cause the O2 sensor to register a rich condition—potentially triggering P2271. Could you please share pre-cat and post-cat O2 sensor readings at idle and 3000 RPM? Also, what is the fuel system status value? Does the fuel system ever transition into closed loop? If so, when does this occur?