1999 SUBARU LEGACY fuel consumption

TROUBLE PROBLEM PARTS, ETC. POSSIBLE CAUSE RANK
5. Engine does not return
to idle.IFuel injection system A
IIntake systemILoosened or cracked vacuum hose A
IOthersIStuck or damaged throttle valve A
IAccelerator cable out of adjustment B
6. Dieseling (Run-on)IFuel injection system A
ICooling systemIOverheating B
IOthersIAccelerator cable out of adjustment B
7. After burning in exhaust
systemIFuel injection system A
IIntake systemILoosened or cracked intake duct C
ILoosened or cracked PCV hose C
ILoosened or cracked vacuum hose B
IDefective PCV valve B
ILoosened oil filler cap C
IBeltIDefective timing B
ICompressionIIncorrect valve clearance B
ILoosened spark plugs or defective gasket C
ILoosened cylinder head bolts or defective gasket C
IImproper valve seating B
IDefective valve stem C
IWorn or broken valve spring C
IWorn or stuck piston rings, cylinder and piston C
IIncorrect valve timing A
ILubrication systemIIncorrect oil pressure C
ICooling systemIOver cooling C
IOthersIMalfunction of evaporative emission control system C
8. KnockingIFuel injection system A
IIntake systemILoosened oil filler cap B
IBeltIDefective timing B
ICompressionIIncorrect valve clearance C
IIncorrect valve timing B
ICooling systemIOverheating A
9. Excessive engine oil
consumptionIIntake systemILoosened or cracked PCV hose A
IDefective PCV valve B
ILoosened oil filler cap C
ICompressionIDefective valve stem A
IWorn or stuck piston rings, cylinder and piston A
ILubrication systemILoosened oil pump attaching bolts and defective gasket B
IDefective oil filter seal B
IDefective crankshaft oil seal B
IDefective rocker cover gasket B
ILoosened oil drain plug or defective gasket B
ILoosened oil pan fitting bolts or defective oil pan B
74
2-3b[K100]DIAGNOSTICS
1. Engine Trouble in General