1997 Mitsubishi Galant Q&A

1997 Mitsubishi Galant Question: car is getting 5-8 miles a gallon, black smoke out tail pipe, hard to start,

1997 mitsubishi galant 165,000. Black smoke out tail pipe, hard to start when it sit for a while, 5-8 miles a gallon, exhaust smell up front. Have done fuel injection flush, changed spark plugs, change idle control value. What else can I do???? -
Answer 1
change the head gasket and take the heads to machine shop to be test it for worn valves seals -