Emission Control Abbreviations: "H"
- HAC
-
High Altitude Compensator
- HAFS
-
Heated Air Fuel Ratio Sensor
- HAI
-
Hot Air Intake
- HAS
-
High Altitude System
- HC
-
Hydrocarbons
- HCAC-VSV
-
Hydrocarbon Absorber Catalyst Vacuum Switching Valve
- HDC
-
Heavy Duty Cooling
- HDC-CTO
-
HDC Coolant Temperature Override
- HFM-SFI
-
Hot Film Engine Management SFI
- HIC
-
Hot Idle Compensator
- HIM
-
Heated Intake Manifold
- HO
-
High Output
- HO2S
-
Heated Oxygen Sensor
- HP
-
High Performance
- HP
-
Horsepower
- HPCA
-
Housing Pressure Cold Advance
- HSC
-
High Swirl Combustion