'03 with 86K has the "malfunction" lite on in the dash. Looked on pg 303 in owner's manual and it seems this is the warning for a problem in emissions system. I checked the gas cap and it seemed fine but took it off and placed it back with several clicks so will see if that turns lite off. Any other suggestions before I resort to dealer?

 

had you just put gas in the tank and the cap was not 3 clicks tight?
thats the only reason a ck engine light would be from the gas cap

go to a parts store and ask for a `code reading`- they will plug a scanner into a port behind shifter and tell you what codes there are
report back here with those and we can lead you thru a diagnosis
codes themself are not a diagnosis- they are clues