FUEL INJECTORS
Deliver
fuel to the cylinders, when they start to fail (usually in pairs) it can be caused by several other issues like the
FICM, dirty oil (not being changed
every 5K miles) low fuel pressure,
mechanical failure or electrical issue. Most injector issues are noticeable at
the beginning of a cold start up and will go away once the engine is warm.
Signs of a bad injector are hard start, rough idle, black or grey smoke. If
ignored this can cause serious engine damage. Do not ignore this issue because
it goes away once the engine is warm!