Thanks to all of you who helped me with my "3.2 Gross Polluter" thread. The state of CA finally reopened the Smog Referee Stations after a two month forced vacation due to state budget cuts and I was able to get the car successfully tested.

Initially I brought this car in from out of state. Because it's a 77 car with a 89 engine it must meet the approval of the CA State Bureau of Automotive Repair Smog Referee for its first smog test. First try it failed miserably.

Then I did a full tune up including plugs, cap, rotor, plug wires, valve adjustment, new fuel and air filters and the car still failed smog.

I discovered the stock appearing cat was gutted and replaced it with a good used one. The brown jumper wire on the ECU was also disconnected. I had the mixtures set and went back for a successful test. The Bureau of Automotive Repair Smog Referee Station issued me a sticker allowing the 1977 car to be smogged as if it were a 1989 3.2 Carrera.

Here are the numbers for 25 mph (1800 rpm) before the tune up:

CO2%: 14.1
O2%: .9
HC (ppm): max 86, measured 268
CO%: max .60, measured .37
NO (ppm): max 717, measured 1435
Result: FAIL, Gross Polluter

After the tune up:

CO2%: 13.2
O2%: 1.3
HC (ppm): max 86, measured 277
CO%: max .60, measured .64
NO (ppm): max 717, measured 1208
Result: FAIL, Gross Polluter

After replacing the cat, brown jumper connected, mixtures set:

CO2%: 15.1
O2%: 0.0
HC (ppm): 41
CO%: .19
NO (ppm): 319
Result: PASS

I find it interesting that HC and CO are higher after the tuneup! With the addition of a cat hydrocarbons went from 277 ppm to 41 ppm. Carbon monoxide was cut by two thirds and oxides of nitrogen three quarters.

So, three smog tests later and four months after I bought this car, the DMV finally gave me license plates for it that read: 6"FQW"530. How's that for poetic justice?

Now we can all breathe a little easier.............until I get my SW chip and premuffler!

Here's a picture of the sticker issued by the state of CA for a conversion car with a newer engine. With regard to CA smog my 1977 911S is now a 1989 Carrera.

 

How did the changes effect the preformance.

 

Overall it runs much better now. It's hard to judge the net effect of each change because most of the changes were made more or less simultaneously. The car was down on power when I first got it and had a miss at idle. The biggest issues were a clogged/restricted fuel filter and one bad plug wire. There was also a noticable improvement after setting the CO. It pulls a lot harder now and idles smoothly. It's a lot quieter with the cat installed but feels a little "corked up". Throttle response seems lazy to me but I am learning this is a Motronic issue that can be improved with a Steve Wong chip.

 

How does Ca know what engine you have? Did you tell them? Would a 77 be required to pass smog in Ca? If so, do you guys have to upgrade all old cars to meet smog tests, or just cars that come in from another state?