Its time for my CA smog check again. Results from 2-yrs ago tests were at margin:-

Speed: 15mph + RPM: 1805 + CO2: 14.7 + O2: 0.6 + HC(PPM): 51 + CO: 0.03: NO: 82
Speed: 25mph + RPM: 1645 + CO2: 14.8 + O2: 0.5 + HC(PPM): 5 + CO: 0.01: NO: 44

HC(PPM) @15mph was at the MAX permissible of '51'. This time may not get that lucky.

1. What is HC(PPM)???
2. How could it drop from 51 to 5 when going up from 15mph to 25 mph?
3. What could be a potential root cause of elevated HC?
4. What can I do to control or fix it?

Thanks much!!!

 

The car has ~83k miles. Has taken good care right from day 1, has not given any problems ever, all routine maintenence done at lexus service stn up until 70k. It included new spark plugs at 60k miles.

 

HC= hydrocarbon

when you go take the smog test go there when your car is fully warmed up the hotter the cat is the more emissions it will burn up

if your in norcal I can smog it for ya....

 

Its time for my CA smog check again. Results from 2-yrs ago tests were at margin:-

Speed: 15mph + RPM: 1805 + CO2: 14.7 + O2: 0.6 + HC(PPM): 51 + CO: 0.03: NO: 82
Speed: 25mph + RPM: 1645 + CO2: 14.8 + O2: 0.5 + HC(PPM): 5 + CO: 0.01: NO: 44

HC(PPM) @15mph was at the MAX permissible of '51'. This time may not get that lucky.

1. What is HC(PPM)???
2. How could it drop from 51 to 5 when going up from 15mph to 25 mph?
3. What could be a potential root cause of elevated HC?
4. What can I do to control or fix it?

Thanks much!!!

Hydrocarbons amount to unburnt gas. It can drop from 51 to 5 when more air enters the engine as it can combust better with more power (or higher mph). Plugs, clogged air filter, cat going (not likely here), oil in the combustion process (yes it happens, but this would only be when way overfilled). The gas can also be bad and I have that issue south of the border.

Wolverine suggestion is great. I would heat that ES cat up out on the highway.