The Check Engine Light may illuminate because of a failed knock sensor. Although the sensor often tests okay, it can fail intermittently, while the vehicle is being driven.
Average mileage: 84,566 (30,000–128,700)
Engine affected: 2.5L 4 Cylinder Turbo
10 people reported this problem
I just bought a used 2008 WRX, just a couple hours later the engine light came on with a misfire code. Went back to the dealer, they replaced the spark plugs & coils, and checked everything out. Two days later another engine light with a O2 sensor, bank 1. They cleared the code, asked me to drive again. Four days later engine light on again after I pushed the car high speed on the highway. Autozone told me, O2 sensor again - but then the light went off by itself. I'm very confused - does the car have a problem or not?