Toyota Repair: 1993 Toyota Pickup Failed Smog, catalytic convertor, smog test

Question
Ted,

My truck failed smog after I replaced the spark plugs & wires, air filter, O2 sensor (upstream) and oil.  It failed because of really high HC.  The results were 126 MEAS at 15mph (max allowed-90) and 63 MEAS at 25mph (max allowed-55).  Should I replace the catalytic convertor?  I did notice that the gasket above where the spark plugs are located (cover) is leaking some oil. Does this affect the smog test?  Also, after the test the coolant started to spill out of the reserve tank.  Please help!

Answer
High HC is usually caused by a misfire, it is unburned fuel, if the engine has a misfire it needs to be addressed first. Coolant exiting the reservoir tank means the engine is overheating I would recommend having it checked for a possible headgasket problem.