Cool 2004.5 Volvo S40 Check Engine Light References. Web my 2004.5 s40 t5 check engine light is going on and off about 2 to 3 times for every tank of gas. Web i recently replaced the oxygen sensors in my s40 but, the check engine light is still on.
I am getting so fed up with this. What does the check engine light mean when illuminated? When this light illuminates, it indicates that the car’s onboard computer, or engine control module (ecm), has detected a fault in the system.
