Possible causes

– Faulty Oxygen sensor
– Ignition problem
– Fuel injection problem
– Engine mechanical condition

Tech notes

There is a factory service bulletin for the following Buick models:

2000-2008 Buick Century
2000-2008 Buick LeSabre
2000-2008 Buick Park Avenue
2000-2008 Buick Regal
2002-2008 Buick Rendezvous
2000-2008 Buick Factory Service Bulletin OBDII Code P1174

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1174 BUICK Description

The Engine Control Module (ECM) performs a fuel trim cylinder balance utilizing the HO2S, when the calculated accumulated voltage exceeds a predetermined level this code is set