C5Lion

I have a month before I need to get a smog test done and need some help diagnosing the problem.

About 6 weeks ago, I got a check engine light to come on. I then proceeded to get the error code and it was a P0431 error - this means that the oxygen sensor downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system. I then proceeded to clear this error and see if it would come back.

It has not come back, but one of the diagnostic checks in the computer has not run. The EVA test (Evaporative System) has still not run and hence I will not pass a smog test. Since then, I have put several hundred miles on the car. I did change the battery a few weeks ago for a different problem and this meant that all the tests had to be run again. I did have a 2nd test that did not run, which was the CAT test, but that has since run.

So what does this EVA test do and how do I get it to run? Here is a copy of the GM Driving Cycle test which supposedly runs all these tests. It is hard to run these tests on the freeways here in Los Angeles. Which specific test(s) is for the Evaporative System?

Is their anything I can check under the hood? My car does have a tune and a Halltech air intake.

General Motors Driving Cycle

A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:
1.Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.

2.Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.

3.Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

4.Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.

5.Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

6.Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.

7.Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.

8.Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.
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Unreal

Are you sure they will not pass with 1 code not done? Most states are like that since the evap needs specific temps/etc to run. You probably can't even get it to run in the summer or when it is really cold. Basically all you can do is keep driving it, and hope the weather cools off so it will run.

If you are willing to tune the car a tuner can adjust the test to be complete.

jedblanks

Most states do indeed allow one not ready and still pass. The republic of CA may be a bit different.

C5Lion

I really don't know if I could pass with one not being done. In California I would doubt it.

I am not sure why the EVA test would not run. It has been very hot in so cal, but the coolant should not be above 122°F when sitting in my garage. I would think the coolant and ambient would be within 11°F.

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup

If I cannot figure out how to get this test run, then I will probably turn to my tuner.

SS MPSTR

Nope - big red flag as I understand it.

Just another reason to hate this state.

Dirty Howie

Leo

I suggest coming out to ACS on Sunday. I'm sure a couple of hours on the track will run all the tests. Explain this to your wife as being necessary to pass smog. Assure her you are not going to have fun


DH

pkincy

From the sometimes reliable and sometimes unreliable internet:


California smog check regulations allow for one (1) incomplete or not ready
monitor. All the reset of the emission monitors must be "complete' or
"ready". Furthermore, the Catalyst Monitor is the one monitor that must be
complete if the vehicle previously had any emissions defects causing that monitor not to be ready; and the vehicle is (after repairs) being retested.

subfloor@centurytrans

Doing the driving cycle thing isn't necessary. If you can get me a copy of your tune using HP Tuners I know how to tweak it to have all your systems show as ready before you even fire up the car.

pkincy

Some things are best discussed in pms, remember NSA is listening and don't they own GM?

1320IN9

agreed, subfloor and i just did this to my car, worked great passed no problem, i wasted so much time and fuel trying to get the monitors set and ready and they would never set, just do it the easy hptuner way

Unreal

It isn't the coolant/etc, it is the ambient temp/etc. Like I said, Arizona and many states have to allow 1 not ready because the stupid evap won't even run 3/4 of the year.

C5Lion

I don't have a copy of my tune nor HP tuners.

C5Lion

I might have to call a smog shop to see if this is true.

C5Lion

Good one Howie, I am going to pass on ACS. I am going to Spring Mountain, however. That is a great track. Are you going?

Dirty Howie

No, too far for me

But I will be going to WSIR the following weekend


DH

SS MPSTR

I got bad info then. When I smogged my diesel last year, I was told all had to be ready.

C5Lion

What do you mean too far? Pack the car up and make a weekend out of it. Bring the wife, she'll love Pahrump. We plan on heading up to vegas for a few days afterward.

Dirty Howie

That would mean being in the car with my wife all that time


DH

SUPERCRUZ

I believe if your check engine light is on, the car will not pass smog even with only one readiness monitor set to Not Ready. Are you sure you did not get a P0430 code. I had a check engine come on in my 09 shortly after purchase. After pulling the code, it indicated inefficient catalyst. The car only had 6400 mi on it. I did a search on the code in the Z06 section of this forum and found there was a TSB for certain VINs with this issue and the dealer installed an updated PCM tune that resolved the issue. Code has not come back since.

Here is the post.

http://forums.corvetteforum.com/c6-z...-cat-code.html

C5Lion

As I said in my first post, I did originally have a P0430 code which triggered the Check Engine Light. I reset it to see if it would come back and it has not, nor has the CEL. I reset it 5 or 6 weeks ago and the error code has not come back.

I just need to get that damn Evaporator Test to run and assuming it passes I can then get my smog test. I still have some time before I need to do this, but I am getting impatient.