Our 04 Reg Cmax is blowing black smoke out of the exhaust. I have noticed there is a small power loss when this also happens. It is when the engine has warmed up.

Could it be somthing to do with the exhaust?

Any ideas what it could be?

Black smoke is caused by excess fuel that has entered the cylinder area and cannot be burned completely. Another term for excess fuel is "running rich." Poor fuel mileage is also a common complaint when black smoke comes out of the exhaust. Black smoke out the exhaust is the least cause for alarm. Excess fuel will usually effect engine performance, reduce fuel economy, and produce a fuel odour.

Some of the causes of excess fuel are a carburetor that is out of adjustment, a faulty fuel pump, a leaky fuel injector, or a faulty engine computer or computer sensor.