Alfa Romeo Forums banner

92 164L failed CA smog test

953 Views 14 Replies 4 Participants Last post by  Ronnald
Folks...this go around the readings, ( reading double the spec's) suggest
the car is running to RICH / not burning all the fuel first thought timing ?

Thank you all Ron
1 - 15 of 15 Posts
Can you post the specs? Which ones are double? It makes a difference in what might be the problem.
When my son's failed CT emissions I replaced the oxygen sensor and it solved the problem. I'm not sure how to link you to my threads, but I think the title was "failed CT emissions today" . It think it was about one year ago.

1992 164L failed CA Smog Specs below

HC MAX = 110 @15mph measured =423
HC MAX = 85 @25mph measured =328

C0% MAX = [email protected] mph meaured =4.66
Co% MAX = [email protected] mph measured= 1.45

NO PPM MAX @ 15 mph =772 measured =465
NO ppm MAX @ 25mph = 711 measured =831
Great googly moogly! You are running very rich. Are you getting any check engine codes?

May be as simple as a bad oxygen sensor or coolant temp sensor, but that should likely be throwing codes. Given that your CO and NOx are both high my guess is that it's run rich for long enough that you'll need a new cat converter. I'm no expert though so I hope I'm wrong.
1992 164L failed smog check

No engine check lights ...Cat replaced in 2009
Just to check here, does the light work? It should turn on briefly when you turn on the car.

Cat may need replacing again. If you run rich long enough it'll kill it. Again, hopefully I'm wrong here.
Your HC is really high too. 4.6% CO is worse than Webers. Not sure what could make the injection so rich; you have an utterly stopped-up air intake? Is one injector dumping in straight fuel with no spray pattern?
Andrew .....Thank you for the heads -up I will have the injectors / air intake checked

Have a great day
You might also have one or more fouled spark plugs. That'll lead to lots of unburned fuel, which equals high CO and high HC.
You might also have one or more fouled spark plugs. That'll lead to lots of unburned fuel, which equals high CO and high HC.
But again, that should be throwing codes like crazy.

Other thing I was thinking of was a failed fuel pressure regulator. But again, that should be throwing codes like crazy....

I still think its the O2 sensor. The symptoms are the same as mine, car ran fine but did not pass inspection, emissions said running rich, no codes or warning lights. Check the voltage output of O2 sensor according to the procedure in the link below. I think I used jumpers into the wiring at a plug in the O2 wire located near the 40A fuses on the firewall. Getting the sensor out can be tough, and getting new one in may require using a tap to refresh the threads. Try to find my old threads "failed CT emissions today".

Oxygen Sensor Information

HI! Rick,
Where is the O2 sensor located top of engine ? by the Cat ? I am not sure ?

Thank you Sir

The O2 senor is located on the top-front of the catalytic converter. It has two wires that travel up the firewall on the drivers side. Its those two wires that I checked for voltage values as per the test produre above. I did my checking while it was still installed, ran the car for cold and hot readings.

1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.