my friends 92 si failed smog today, and i dont want to change everything out till it passes. What would cause the HC and NO(ppm) to be high? car is supercharged also I/H/E thanks

 

Could be a number of causes... when was the last time the oxygen sensor was replaced?

 

sure to fail if the timing is retard d more than 2 degrees of OEM settings

 

did it fail visual, or the pollution test?

 

if he s got headers and tubing infront of the cat. has increased..ull get better flow..more power..the downside is that better flow = less heat to burn up the HC s...ive got headers on a S/C also..and ive gone to a OEM cat..hopefully that ll get me enough back preasure and heat to burn up the dirt..the smog shop couldnt give him any suggestions to clean up the exhaust??..they should if they re a repair shop also..or are they a , test only shop?

 

pay someboyd to pass you

 

If you can give me the exact HC and NOX in PPM (parts per million) and their standards, I might be able to tell you whats wrong with your car... Remember, HC is unburned fuel and NOX is made when combustion temp reaches 2500°F... There are only two probable causes that I could think of... it's either the car has a bad cat or a lean misfire that cause the HC and NOX to go high..

Regards,
Charleston



[Modified by CivicFerio, 10:48 PM 1/1/2002]