Question about 1997 Honda Civic
Failed California Smog Check. Will a complete tune up fix the problem? If not, what should I repair / replace?
ASM Emission Test Results:
15mph - RPM = 1902 %CO2 = 14.3 %O2 = 0.6
HC (PPM) = 160 (max 66)
CO (%) = 0.74 (max 0.57)
NO (PPM) = 3198 (max 487)
25mph - RPM = 1685 %CO2 = 14.3 %O2 = 0.6
HC (PPM) = 174 (max 49)
CO (%) = 0.76 (max 0.55)
NO (PPM) = 2755 (max 774)
How well does the vehicle run?
Assuming that the engine did pass the EGR function test on the emission test results, and the MIL (Malfunction Indicator Light) or check engine light is not on when the engine is running, and if you are not sure when the last time it was that the engine had a complete tune-up, with distributor cap, ignition rotor, spark plugs, spark plug wires, air and fuel filters, then a complete tune-up would certainly help, and if the engine oil and oil filter have not been changed in a while, then they should also be changed before an emission test because long used engine oil traps carbon and it will show up as higher CO on the emission test because the emission analyzer will be able detect the higher CO from the engine oil through the PCV valve.
However, it would seem from those HC readings that there is a vacuum leak, and carefully inspect all of the vacuum lines for any cracks or damage, (especially the vacuum line to the fuel pressure regulator) because cracks in the vacuum lines seem to like to hide underneath the lines.
The emission label under the hood should have the vacuum line routing diagram printed on it, and the vacuum lines should all be checked to be certain that they are all connected correctly.
Here is the firing order diagram for that vehicle to help assist you tune-up the vehicle.
Posted on Jul 10, 2010
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Aug 19, 2017 | 1994 Honda Accord
Aug 10, 2011 | 1999 Chevrolet Silverado 1500
Feb 24, 2011 | Chevrolet Astro Cars & Trucks
May 20, 2010 | 2003 Chevrolet Suburban 1500
Mar 21, 2010 | 2002 Jaguar X-Type
May 31, 2009 | 1985 Volvo DL
Mar 27, 2009 | 2000 Saturn SL
Feb 11, 2009 | 1996 Nissan Maxima
Jan 12, 2009 | 2001 Isuzu Rodeo
1,134 people viewed this question
Usually answered in minutes!