Need help passing smog. The car is a manual 1993 civic dx coupe with a D15b7. Car was sitting for months before I bought it as a project for my son. We replaced the head gasket, valve seals, distributor rotor and cap, spark plugs and wires, fuel filter and air filter.
these were my smog results.
can anyone give me any advice in where to start. Thanks

 

If its passing at higher rpm, that tells me that the cat converter is clogged up.,, Or there is a restriction in the exhaust, (of course I may be wrong also) If it were my car, I would start by checking valve clearance. Then check the timing belt timing, one tooth off and the cam timing gets weird. After that, make sure the ignition timing is correct, Look up how to check the ignition timing. Make sure the spark plugs are clean and dry. Once all that is checked, take the car on the highway and beat it like a rental car. Get the cat converter good and hot, then drive it hard, Give it an Italian tune up. The reason I say to do that is, looking at your paperwork, the car fails at lower RPM and passes at higher RPM. Also a can of Seafoam in the gas tank cant hurt. If the car has been sitting for months, there is a possibility that the fuel injectors are grumpy due to the crap gas you have in California

 

Thanks for the suggestions. I’ll start there. The car has over 300k miles and I that’s the original catalytic converter so maybe it is bad.

 

Yeah why actually read the results and see that you failed the ignition timing functional check.

 

Ended up replacing the catalytic converter and adjusting the timing and it passed. Thanks for all the suggestions.