How I beat the CA Smog Nazis (1 Viewer)

[lobo loco]

Well I thought I'd post this for the benefit of anyone having similar issues with the CA ( or other states for that matter) Smog Nazis. My original CA 78 FJ40 has always struggled to pass CA tests and I live in a county that requires the biennial 'test-only' check.
Every two years I have had to deal with the various smog check stations with techs that are younger than my truck and have to be shown how to open the hood. To make the story short I
went out and had a test done and my 40 failed one of the tests for CO. I had the carb rebuilt for the last check two years ago, and it just barely passed then, so since the truck runs just great as is and everything is to spec, I decided to have a catalytic
converter put on it, rather than to deal with unnecessary diagnostics and repairs by folks that have no familiarity with the vehicle. For about $200.00 and some change I put a cat on, and did so with flanged mounting, so that if necessary, it can be removed and replaced with a straigt pipe, should heat or performance be a problem. Thus far, it seems to have made no change to performance and heat does not seem to be a problem, but I'll have to wait until we have some 100+ days to make that call. Here's my numbers before and after the cat. The numbers with the cat compare with my late model vehicles and the cat should solve the problem for many years to come!
Test results before the cat…

.......... HC ............. CO% .............. NO
.......... max avg meas max avg meas max avg meas
15 mph … 196 52 33 1.59 .024 2.43 1507 553 207
25 mph … 161 44 21 1.39 .021 1.38 1367 474 171
After the cat was installed…..
15 mph … 196 52 8 1.59 .024 0.13 1507 553 89
25 mph … 161 44 6 1.39 .021 0.23 1367 474 85
The change in the numbers just seem amazing to me!! I would have never guessed they would be so good. About 10% of what's permissable!!
Another side benefit is that it runs a bit quieter, but still sounds good. I have a set of Downey headers, 2.5" pipe, and a Flowmaster muffler on the truck. Some pics of the new cat
below...

 

[BDSeff1fitty]

no clue what half of that means, but its obvious some of the numbers dropped a lot. how do you like your downey headers?

 

[lobo loco]

They are great. Had to put them on due to a cracked original exhaust manifold. Sound is great...had some folks ask me what kind of V8 I had in it. While most headers usually result in an engine running leaner, I've never had the problem. It's obvious that you don't have to deal with the CA BS about smog...consider yourself lucky.

 

[Doug_S]

Great job. I've always wondered how it would work to just add a cat. Now I know... I'm getting ideas for the time when the Obama administration makes smogs checks mandatory for all vehicles.

 

[mano002]

I used to work with a guy who had a flanged x-pipe on his 350, so he could take it out and put 2 cats in, he would re-jet the carb to make it pass as a V6. It would run like crap, but pass emissions, and then un-do all his mods. It would take him about a day to set-up, pass the test and un-do it all.

 

[srgould41]

I'm getting ideas for the time when the Obama administration makes smogs checks mandatory for all vehicles.

Hush your mouth!

 

[rpfzj80]

You may want to remove the cat fairly soon. The extra CO just means you're running rich and without a feedback system to switch between lean and rich, the cat will likely deteriorate/die before the next smog check.

The problem you're seeing is probably not the carburator and is more likely due to another issue such as a poor/non-performing air injection system. If you look at your numbers you may see little or no oxygen, fairly low HC, fairly low CO2 and very low NOX.

Over the next couple years it may be worth walking through the air injection and other systems/controls to make sure they are doing what they are supposed to...then you won't need the cat. But hey, that's just the perspective a licensed smog nazi. : )

Rich