88 Carrera failed CA smog

[Netspeed]

So I failed the Calif. smog test....again. I did the trick of driving it like Patrick Long before the test to get the cat hot and it still failed on the HC. CO and NO pass but barely. I saw a thread on here about the altitude correction switch having six settings but that might apply to an older ECM. I have the round device next to the fuel pump relay. Question: is it adjustable and and by how much?

I am starting to burn oil at prolonged idle but if the cat was failing I would think all three measurements would be high across the board.

I might just resort to the denatured alcohol to lean it out (very temporary).

Any and all advice is greatly appreciated!

[JWLindsey]

The cat has probably checked out. I barely passed on NO on the 180k mile cat with the brown wire disconnected but the other values were not too bad. Changed out the cat to a new DEC unit from Pelican, connected the brown wire, and the car passed with flying colors two years and 5k miles later. I don't think the fuel switches and other tricks will do much but a new cat works wonders.

-JWL

[lucittm]

Install a new catalytic converter and take a half of a turn on the mixture screw next to the fuel distributor (I think it is counter clockwise to go leaner). You will pass, then put the screw back where it was unless you think it runs better and there are no adverse conditions, such as over heating.

Mark

[Netspeed]

Originally Posted by lucittm

Install a new catalytic converter and take a half of a turn on the mixture screw next to the fuel distributor (I think it is counter clockwise to go leaner). You will pass, then put the screw back where it was unless you think it runs better and there are no adverse conditions, such as over heating.

Mark

Mixture screw?? I looked in my Bentley manual and I couldn't find it....

[JWLindsey]

Don't think ye olde Motronic has one. New cat should make it money.

-JWL

[E Sully]

[Joe Bob]

02 sensor.....

[Netspeed]

Originally Posted by E Sully

Correct but that's just for idle mixture....

[Netspeed]

Originally Posted by Joe Bob

02 sensor.....

I'm leaning to that and a new cat....

I get a free retest so I'm going to check the Motronic and see if it's not in position 3 (Steve Wong suggested as it's the "running leaner position") and maybe a touch of denatured alcohol just in case.

[db_cooper]

Connect the brown wires pin #10 when doing a smog check. They wire on on the harness going to the DME unit.

[Netspeed]

I'm playing it safe. I just ordered a new cat from Pelican. If I had access to an exhaust gas analyzer, I could test and test and test to see which method works best.