Join the community and post your question. Use our Ask-A-Tech for free now! ASE experts standing by.

Forum > General Smog Check > Question

What Would Cause High HC 1992 Cadillac

I just purchased a 92 Cadillac and while I passed the smog check the HC both on the low test and the high test were almost at the limit. The smog tech thought that the car might need a new set of plugs wires cap and rotor, but in looking through the service records this was all done about 6,000 miles ago and they used OEM parts. what other areas should I check? the records indicate that all of the previous emission testing has passed with flying colors and I would like to maintain the car in a top running form.

Answer:

You do not mention your Cadillac's CO results so we'll assume they are low... perhaps even 0.00, leading you to believe your Cadillac does not have CO problems. If this is the case you'll need to check your Cadillac fuel feedback system. Low CO (lean fuel condition) would cause high HC as well. Things to check for would be vacuum leaks, dirty fuel filter, possible faulty MAF (Mass Air Flow) sensor, dirty fuel injectors, and the like. Basically faults which would cause less fuel than needed fuel entering the combustion chambers, or faults which would allow "unmetered" air to enter the combustion chambers. Unmetered air would be any air source (leak) after the MAF. Follow this link for What Causes High HC Faults. posted by SmogTips Support

Related questions and answers you might find useful:

Learn How House Cleaning Business That Makes Over $2000 Every Week! This Business Is For Anyone Who Wants To Make More Money & Take Charge Of Their Future Check The Link Below https://PROFITFROMHOUSECLEANING.COM by Lela

How Do I Get a Smog Check Waiver? by Margaret

Do I Need a Smog Check This Year? by Joy

Mini Cooper DMV Registration Due in 5 Day Won't Pass Smog by anne

2001 Jeep Grand Cherokee Laredo with K&N Air Filter by David

View SmogTips.com in: Desktop / Mobile