Charlotte944

Chapstick951:

The problem you are seeing is with how the O2 sensor and the WB AF gage operate. The big issue is that the power supply circuitry in these inexpensive WB gages is not regulated. Consequently when the vehicle's system voltage drops (like when you run the A/C, headlights, fog lights, rear window defroster), the reference voltage to the comparators in the WB gage also drops and you get a lean indication.

I've had a WB gage for a long time, and I was freaking out right after I installed it in my old '84 NA. During the day it read OK, but at night, or when the A/C was on it indicated lean. Since it was a new gage, and I had just had the emissions checked, I decided to test the signal at the O2 sensor. When I determined that the sensor was doing what it should be doing I realized what was going on.

The easiest thing to do is use a DVM to read the O2 sensor out put at the connector and then bounce those readings against your WB gage.

Lorax

Its great having no emissions regulations... and I'm within 45 minutes of atlanta.

PuttingThePoorBackInPorsche

I think you're missing my point - if you're blowing clean air (per their standards) out the tailpipe with or without a cat or such-and-such an aftermarket part, who gives a flying fig?

If the goal is clean air, then test for clean air. All the other B.S. is strictly for power/money interests.

BTW I believe it costs a LOT of money for an aftermarket parts manufacturer to get a "CARB approved" stamp on a part. Wonder why that is. . . hmmmmm. . .

chapstic951

It is the same reason that ski resorts still require snowboarders to use a leash. Those of you who ride know what I am talking about. It comes down to staying with what is familiar, easier to enforce and keeps things consistant.

skene

Charlotte,
I can't remember exactly, but the numbers were very close to passing. HC was half the limit, Nox was a hair under (limit of 1400 i think?) and the CO was .46 with a limit of .44 at 15mph and at the limit of .5 at 25mph.

After fixing a disconnected vacuum line and replacing some electrical stuff it failed CO again and both NOx limits....but it was also a much hotter day out.

I'm probably going to send it to a shop since I know I've got something wrong with my #4 cylinder but don't feel like figuring it out. That plug was black with carbon build up on it and the other three looked perfect.

Sorry for the hijack btw.

chapstic951

No worries. I more less got my question answered. Basically make sure the engine is properly tuned or wait until my car is 25-years old and remove the cat.

Tom M'Guinn

It's getting worse next year too. My smog guy this weekend was showing me the new test that is coming in california -- the "EVAP" test where they pressure test your entire fuel system for "evaporative" leaks. The limit is 0. A new market is about to spring up in california for replacement fuel filler neck seals, fuels lines, etc.

chapstic951

Tom,
We are a step ahead of you there. VA already does the fuel tank pressure test. This is what you get when every 3rd VA resident is a politician.

Ski

Sounds like just another way for CA to try and make more money.

Cory9584

You should put a dummy cat so you will pass a visual test, then just tune it good and you should be able to pass with no trouble.

skene

VA only tests the gas cap I think, not the whole system. At least that's what they did for me. They might have been lazy.

PuttingThePoorBackInPorsche

CA does that now. It's part of the standard smog check (test the cap).

I've heard of people doing the fake cat/gutted cat thing. Probably pretty easy to get away with, but why risk it? It takes only a couple hours to bolt a real cat up, pass your smog and then (if you really want to) another couple hours to drop it out again.

smarlow2

If you are failing emissions by a small margin, one thing you might want to consider is if you had the cat up to optimum operating temperature. The cat is less effective at lower operating temperatures. I took my 89 through emissions with the cat on and they had to stop the test to recalibrate the equipment and the car was off for about 15 minutes. They then started it up and it failed by a very small margin. I took it to get retested the next day and made sure it was hot before I tested and it passed with no change in equipment.