However, it is best to fix it as soon as possible, because it will cause the check engine light to illuminate If the check light is on because of the P0440 code and you ignore it, you will not notice when the ECM shows the check light due to more serious engine problems. What Are...
Fortunately, many OBD II problems are relatively minor and have little impact on engine performance or reliability. But some do. The only way to know for sure what is causing the MIL lamp to come on is to plug a scan tool into the system and read the diagnostic fault code(s) to find ...