Especially in older cars, your positive crankcase ventilation valve will get dirty and gummed up, which can cause cause excessive fuel usage. Fortunately, the pcv valve is easy to replace and very cheap to buy for almost any car. You can test your old one by taking it off, cleaning it out with some carburetor cleaner, and blowing (or sucking, depending on the end.) If it makes a nice solid seal, then it's still good and can be reused.
by jsinton on May 06 2011
this tip works for 81% of voting Fuelly members.