My 91 Integra failed CA smog 2 weeks ago. Just wanna share things I did to pass (barely). I'm not a smog expert and I'm not saying you'll get the same result but with good intentions, here I go.

Information about my car:

236XXX original miles on the engine and transmission.
AEM short ram intake with K&N filter.
3A Racing exhaust after the cat (never changed/replaced any other exhaust components).
The rest are stock.

My smog result from 2009



My failed smog result from 2011 (HC is lower from 121 to 87)



My passed smog result 10 days later



http://s183.photobucket.com/albums/x104/pawinc/Smog/

I did the following in order before I took the second test.

- Seafoam my car. Half to the vacuum line and half to the crankcase. (I was so tempted to try "guaranteed to pass" but I didn't)
- Drive around 150 miles.
- New full tank of gas (87 Octane)
- Oil and filter change (Usually use 10W-40 but changed to 10W-30 this time)
- New cap & rotor from Acura dealer (cost me $40, personally I didn't think it help much)
- New NGK spark plugs
- Valve adjustment (noticed that most of them were little too tight).
- Retard timing. I thought I retarded from 18 BTDC to 14 BTDC but the smog tech recorded at 16 BTDC (my spec is 16 + or - 2)
- Drove around 60 miles to smog but smog tech was busy so I went to work for 5 hours.
- Made appointment this time and drove around 15 miles before the test (mostly on the freeway with RPM around 4K)
- Waited less than 5 mins before smog. I barely passed but I guess I don't have to worry about it for another 2 years.
- The only thing I don't understand is how they expected older cars to produce lower emissions.

Good luck to all.