I have a 95 Civic DX 1.5 that will not pass CA smog. Needs to be below 72 on the hydrocarbons and was at 74. I have replaced the plugs, plug wires, PCV valve and hose and Catalytic converter. After the Cat Converter was replaced the hydrocarbons got worse and went to 150. So needlesss to say I am beyond baffled . Car runs great and has no blatant mechanical problems that I can detect. Any suggestions would be great. Thanks

 

Some Lucas or Seafoam fuel system cleaner that goes right into the fuel tank is:
A. Cheap, no more that ten bucks for a bottle
B. Great for your car no matter what the result
C. Just might clear things out enough to get you a pass on the smog test

 

Does the engine warm up to proper temperature? Over cooling (bad thermostat or wrong thermostat) will lead to a rich run and high HC.

 

Hello,
Sorry to here about the smog problem. Have you replaced the o2 sensor, that tells the emc the amount of oxygen in the exhaust and to run rich or lean. The new cat works best when it is hot and not right after it is replaced drive a few day then retest. The Seafoam idea in the last post is also good, I had a 1993 Mercury Tracer Lts that had the same problem every year for the last 4 years it would not pass.The frist 3 years I changed the Cat (cheep one $100) and the o2 sensor also put seafoam in through the pvc hose (be careful can cause damage if not done right,and the car will smoke like your house is on fire) and it passed. The last year the car had too many problems to make it worth fixing. I got a Texas air voucher for $3000 and got my new 2010 Civic Lx. Hope you find the problem and pass. Thanks, 2010civiclx

 

It is heating up properly. I have not replaced the O2 sensor. That is next. I will try the Seafoam and keep my fingers crossed. Thanks for the advice. I will let you know what happens.