Catalytic Converter and Smog (CA)

[Sholom770]

Car failed smog (test only station) because of high NO readings. Had mechanic review smog report. He then tested cat. and said that the readings showed it to be inefficient. Temps were the same at inlet and outlet. He said that if it were his car he would replace the cat. He was talking about the cat at the top of the engine, just below the exhaust manifold. I ordered the work done, which they sub out incidentally, and they also charged me the exact same amount that they paid the muffler shop (I also do their books). I took it back to smog shop and found out that the new cat was UNDER the car. Never knew I had two cats! And I thought they were going to replace the other cat. Finally passed smog, had to run test twice because car failed AGAIN the first time. Let it warm up longer and it passed. BUT, HC's went way up from the first test when it failed initially. Any ideas? Also changed the upstream o2 sensor (Bosch) at the same time. Don't want to blow out the new cat with high HC's. EGR is all new. Thanks!

[Doctor J]

You may do a test for the EGR performance I suggested many times.
get the vacuum gage, tape it to the windshield, detach the hose from EGR valve and hook it up to the vacuum gage, warm up the engine and acelerate to 15 mph with medium trottle to simulate the ASM-1575 test. the needle on the gage should indicate about 15 inches on the vacuum gage.
If this does not happening, test the vacuum hoses, vacuum modulator, bi-metal vacuum valve and vaccum ports in the throttle body.

[scoathy]

the manual references the PCV and evaporator (charcoal) canister for HC specific emissions.