94AccordEXWgn_5

Hi, I'm new to the forum but a long time Honda owner.

My 94 Accord EX Wagon (5-spd manual, 214K mi) failed CA smog emissions test for high HC @ 15 mph (69 ppm measured; 61 ppm max) and barely passed 25 mph HC (right at the limit - 36 ppm) and 15 mph CO (right at the limit - 0.51%). See test results below.




Prior to the smog test, I had my local independent Honda shop inspect the EGR ports and check the other EGR related bits. They ports were gunked up and the shop cleaned them out. A bit of background, my car failed smog in 2011 and the diagnostic shop recommended a catalytic converter replacement and the car passed with flying colors. In 2013, the car failed w/ high HC at 15 mph and the EGR port clean out solved that problem and it passed the re-test.

Following the recent test fail, I replaced the plugs - NGK (even though they were only 6 months old and had 2,500 mi on them), wires - NGK; rotor, and cap thinking it was an ignition issue, I replaced the O2 sensor - Denso (existing sensor was three years old) for good measure since the CO was close to failing. The re-test results were worse. The car failed at 15 mph HC (112 ppm), 25 mph HC (39 ppm) and 15 mph CO (0.75%). See results below.





Any suggestions on what to do next to get it to pass? I've read a few threads but the diagnosis seem to run the gamut from engine running lean or rich, exhaust leak, gasket leak, loss of compression, vacuum leak, etc. I was so close the initial test (+8 ppm HC) and now worse off after the changes. Any help would be greatly appreciated. Thanks in advance.