What causes high HC emissions?
Excessive HC results from ignition misfire or misfire due to excessively lean or rich air/fuel mixtures.
- Engine Misfires
- Ignition System Failures
- Excessively lean air/fuel mixture
- Excessive EGR dilution
- Timing Issues
- Catalytic Converter
- Worn piston rings and cylinder walls
- Carbon deposits on intake valves
What causes high CO emissions?
High carbon monoxide levels are caused by anything that can cause a rich conditon.
- Excessive fuel pressure at the injector(s)
- Leaking fuel injector(s)
- Faulty O2 sensor(s)
- Defective fuel pressure regulator
- Defective EVAP system
- Plugged PCV valve or hose
- Catalytic converter
What causes high NO emissions?
NOx are produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures & high pressures.
- Cooling system problems
- Fuel Mixture: excessively lean air/fuel
- EGR System Problems
- Overheating Issues
- Faulty O2 Sensor(s)
- Excess Carbon on Valves,
- Catalytic Converter
- Timing Issues
- Carbon deposits on intake valves
