What are HC readings?

What are HC readings?

Find “HC PPM” within the tailpipe section. You read this as hydrocarbon parts per million, and it means the number of hydrocarbon molecules for every million molecules emitted through the exhaust.

What causes high levels of HC in air?

Excessive HC results from ignition misfire or misfire due to excessively lean or rich air/fuel mixtures.

What causes high carbon monoxide ( HC ) levels?

Excessive HC results from ignition misfire or misfire due to excessively lean or rich air/fuel mixtures. What causes high CO emissions? High carbon monoxide levels are caused by anything that can cause a rich conditon.

What does elevated hydrocarbon ( HC ) emissions mean?

To find these kinds of emission failures, you need access to a TSB database such as that available through a computerized repair information system such as AlldataDIY.com. Elevated hydrocarbon (HC) emissions usually indicate ignition misfire due to fouled spark plugs or a bad plug.

Why are HC and co higher in a cold engine?

HC and CO will be somewhat higher as a cold engine warms up because the fuel system may still be running in open loop. Until the engine reaches a predetermined temperature and/or the oxygen sensor gets hot enough to produce a good signal, the PCM will supply a relatively rich mixture while the system is in open loop.

What does it mean when your HC level is high?

High HC’s mean gasoline is going in and out without getting burned. Valve and ring problems can cause this, so have a wet/dry compression test done, and have the valve adjustment checked. O2 sensor problems can cause this too, but diagnosing those requires a mechanic experienced and with the proper tools.

Excessive HC results from ignition misfire or misfire due to excessively lean or rich air/fuel mixtures.

Excessive HC results from ignition misfire or misfire due to excessively lean or rich air/fuel mixtures. What causes high CO emissions? High carbon monoxide levels are caused by anything that can cause a rich conditon.

What causes high hydrocarbon ( HC ) in a fuel?

What Causes High Hydrocarbon (HC)? Below are common failures which are likely to produce high Hydrocarbon HC. Hydrocarbons are basically raw fuel, otherwise known as Gasoline. High Hydrocarbon (HC) emissions are almost always a sign of poor fuel ignition.