HELP Emissions test failure !

[fc227]

HELP !!!!


I went to have the GN Emission tested. It failed. Went to the DMV. Even though the cashed my check they will not renew my reg. Until the car passes.


Ok it failed two years ago, but they let me reregister it. Here are the readings from two years ago & today


2006 2008
HC - CO – NOx HC - CO - NOx
Limit 132- 0.42 - 921 132 - .042 - 921
Tested 78 - .71 - 802 57 - .02 - 1407
Fail Fail



The difference between this test and two years ago
1. New Cat
2. Replaced PCV hose, because it was collapsing.
3. Regular gas two years ago Vs 93 octane this year

Same chip, Mike Pitts emission chip, fuel pressure set to 40#’s


Now when I went to remove the cover for the EGR valve. After I removed the cover, I found the hose to the EGR disconnected. I do not now if I pulled the hose off removing the cover. But I did press the back of the EGR valve and the engine ran rough but did not stall. Plus I got black soot all over my fingers (must be when I was running the race chip, I could have popped the hose off at the same time.

Now with that said, I did block off the front and rear exhaust cross over when I did the heads. But I can’t remember if I plugged the center holes. I must not have since there is exhaust soot on the EGR valve. I really don’t want to pull the intake.

It looks like it running lean, so I will up the FP from 45 (BLM’s are around 134 now). This should help the NOx?


This is the first time I installed an emissions part and it got worst.


Any ideas, I am running out of time.

 

[fc227]

here are the readings


2006

HC
limit 132 tested 78 pass
CO
limit 0.42 tested .71 Fail
NOx 921 tested 802 pass


2008

HC
limit 132 tested 57 pass

CO
limit 0.42 tested 0.02 pass

NOx
limit 921 tested 1407 fail

 

[GNVYUS 1]

We'll need more info, like the whole list of specs from your Scanmaster while idling etc.

Upping the fuel pressure from a base of 45 is asking for trouble, it won't pass for sure if you do that. Most likely you have a leak causing the blm to go lean and your raised fuel pressure is making things worse as the chip is probably designed to be run at 42 or 43psi line off. Boost leak test it and see what happens.

Things like old plugs ( model/plug gap ), wires, 02 sensor, weak coil etc could all be a culprit.

Sounds like the EGR is working so the tower must be open inside the intake.

I bet in the emissions section there are tricks to pass like adding E85 etc.

 

[salvageV6]

Your EGR most likely isn't working.

You need to check for vacuum and voltage.

Find out at what TPS voltage or RPM, above idle, the EGR PWM voltage in that chip is supposed to start to work at.

Do you have ported heads or any EGR tract modifications?

 

[fc227]

Here is a Power logger file. (This was with the FP @ 38#)

The BLM's are fine when I am running another chip.

What I don't understand is why the NOx is so high compared to two years ago, since nothing has really changed. Unless the EGR hose was unplugged (that would also explain the high BLM's becasue of a leak). All I did was put a new working cat on. The old cat was gutted.

Also I got exhaust soot on my fingers from manually moving the EGR valve and the engine did run rough when the EGR valve was open


Yes, I do have ported heads the TPS @ idle is .42 and @ WOT 4.55

 

[TurboTerry87gn]

nox is the result of high temprature and pressure causing nitrogen and oxygen to combine. The purpose of the egr is to recirculate exhaust back into the intake to lower the nox.

My egr went out on my truck a few years back and I did a search on nox.

 

[86BLACKT]

I used a TT emissions chip and bought a cat from Full Throttle and passed. My car is registered historic now, so I just sold the cat. I still have the chip if you want it. Car runs terrible on chip. I stopped around the corner put it in, went through test, pulled out, put my good chip back in!!

 

[fc227]

I have TT emission's chip. But that ran leaner than the Pitt's emission chip.

The spark plug are autolite 24's gapped @ .035 . Only about 3K miles on them

 

[86BLACKT]

Did you contact Erik, and tell him what you need??

 

[fc227]

Yes, I did . He was very helpfull.

But I decided to keep the car like it was two years ago (since the test was close to passing) and used the "pitt's chip that I downloaded off of gnttype web site.(thats the chip I used two years ago).

There is nothing wrong with Eric's chip. I decided to go with something I all ready tried. Maybe I should have used Eric's chip.

It has to be the hose that fell off the EGR. I will have it tested again tomorrow. If it fails again . I will work from there.

 

[86BLACKT]

Mine was blowing off too. I later found EGR was bad and IAC a little later, both causing rough idle. Just FYI, probably not related.

 

[salvageV6]

Before you go testing make sure the EGR is working by runnning the car with higher tps such as .60 or so and make sure the vacuum is working and the valve moves on it's own.

If not you may fail again.

That is why you need to know at what point the EGR PWM signal starts in that emissions chip so you can test and simulate it in the driveway to verify the systems proper operation.

Hopefully it's not load related and simply rpm or tps signal triggered.

Depending upon what hoses blew off you may have a bad check valve in front of the EGR vacuum circuit near the fuel pressure regulator there is one.

Don't go into boost on the way to the test or the hose may be blown off again when you get there causing another failure.

 

[fc227]

Thank you for the suggestion. To do this I need to get the TPS to read .6 volt while the engine is idling?

I will try this with both the Pitts and the TT chip(s).

 

[fc227]

For the "Pitts" emission chip it looks like the EGR comes on @ 3.9% TPS and off @ 2.00% TPS.

 

[diomedes]

Man in Texas I use to get alot of trouble about passing emissions, not sure but you might want to check at your autoparts store and use the emissions cleaner, it worked on my friends old k5 blazer after he failed the first time.

Or just find the right emissions shop :wink: Thats how I would get by.

They are out there!!!

 

[cdsttype]

In Short If The Egr Is In Fact Working Raise The Co So The
Cat Can Activate Too Low Co And The Cat Will Not Reduce Nox
And The Combustion Chamber Temps Will Be Too High With That Lean Mixture.

 

[turbo39151]

I used the following:
1 can seafoam in the tank; 1 can seafoam through the vacuum system- Flushed the oil afterward and put new oil and filter. Had about quarter tank of fuel and added about 1 gallon of denatured alcohol (you can buy at Home depot)

Emissions were virtually non-existant. (20 year old cat btw) Super strict CA emissions to boot!:smile:

good luck.

 

[fc227]

Would one gallon of denatured to 5 gallons of gas be to much alky ? . Since the computer will be trying to correct all the time.

 

[turbo39151]

When I added it to mine, it did stumble a little here and there but all I need it to do was to stay running. The Smog tech was the one who suggested it.

 

[cdsttype]

Your Car Is Too Lean Bring Up The Co If Your Mechanical
And Ignition Systems Are Sound The Hc Will Still Be Good
Half The Allowable Co Is A Good Number Forget The Hocus
Pocus If You Have A Cat And An Egr It Will Pass With The Proper Tune .