Hydrocarbons


#1

I would like to find out what would cause the hydrocarbon readout from an emmission test to almost double in two years. The maximum allowable is 49 ppm.

I went from 27 to 48 in two years. Any ideas?


#2

Unburned hydrocarbons will cause a high hydrocarbon reading. How long has it been since you changed your plugs, air filter, O2 sensor, or ran some injector cleaner (if so equipped) thru it?


#3

Thanks for your suggestions. I will investigate the past services done on this vehicle. Luckily, I have all the service records.