Excessive Fuel Consumption: Aerio

Faulty spark plugs. See IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES article.
Improper ignition timing. Check ignition timing. See IGNITION TIMING in ON-VEHICLE ADJUSTMENTS article.
Faulty ECT sensor. See ECT sensor related DTCs in appropriate SELF DIAGNOSTICS article.
Faulty MAF sensor. See MAF sensor related DTCs in appropriate SELF DIAGNOSTICS article.
EGR system malfunction. See EGR valve related DTCs in appropriate SELF DIAGNOSTICS article.
Faulty TP sensor adjustment. See THROTTLE POSITION SENSOR in ON-VEHICLE ADJUSTMENTS article.
Faulty fuel injector(s). See B-1: FUEL INJECTOR CIRCUIT INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.
Fuel pressure out of specification. See FUEL PRESSURE under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article.
Check for low engine compression. See MECHANICAL INSPECTION in BASIC DIAGNOSTIC PROCEDURES article.
Check brake system for dragging brake. See appropriate DISC & DRUM article in BRAKES.
Check for slipping clutch. See appropriate FWD or RWD article in CLUTCHES.