2004 Malibu 3.5L Engine Light On with P0455, P1125, and P1135 OBD-II Codes - What Causes These Faults?
My 2004 Chevrolet Malibu 3.5L has recently developed three OBD-II trouble codes: P0455, P1125, and P1135. The engine light comes on, and the vehicle enters reduced power mode. After clearing the codes, the car runs normally for about a week before I start receiving a 'check gas cap' message. A few days later, the engine light returns and the car goes into limp mode. My concern is whether P0455 could be triggering or contributing to the appearance of P1125 and P1135. Given that these are separate emission-related systems, I find it hard to believe all three components failed simultaneously. Can anyone confirm if these codes are independent issues or if one code is causing the others?
The P0455, P1125, and P1135 codes are likely separate and unrelated issues. P1125 specifically relates to the oxygen sensor in the exhaust system and is a common cause of limp mode activation. While P0455 indicates a large leak in the evaporative emission system (often due to a faulty gas cap), it does not directly trigger P1125 or P1135. Each code points to a distinct component failure, so they are not interdependent.