I failed Smog this morning, numbers/setup as follows:

JRSC D16A6, running JRSC fuel management (yes I know it sucks, lets not worry about it for now), stock boost. Car has DC header, 2.2.5 inch exhaust, not much else that should effect emissions.

Numbers:

RPM CO2 02 HC(PPM) CO NO
1831 12.7 2.6 116 0.70 2909
2025 13.9 1.7 31 0.15 1092

Everything passes but the NO levels. Now as I was driving home, I got it into some higher revs, and heard a little bit of ping. Thinking that I had already solved this problem (and the car is running 93oct) I cracked the hood when I got home. I realized that last night in preparation for my smog test, I adjusted my dizzy timing. Unfortunately I adjusted TOWARD the firewall, forgetting retarding is toward the rad.

By looking at the numbers above, could I pass smog simply by increasing my fuel pressure to above 50Psi to cool the cylinders and retarding the dizzy timing?

Any help is appreciated, I am thinking about trying again this afternoon, but I don’t want to spend the money if there is no way it will pass those numbers with these adjustments.

Thanks guys!

 

Well not really... and the reason is....

AT your 15mph reading your HC is at 118ppm. Even a slight adjustment of FP and your over.

Timing might help but not to the extreme your NOX is at @ 15mph. It might lower by a hundred or so. If you had it advanced that much you were probably looking at a 22 degree advance and the A6's spec is 18btdc. You might have gone so far that it raised the HC's also.

I believe Jackson recommends retarding the timing so I would check this out too.

What I see is the O2 reading very high. On an A6 it should go to 0.0.
So either you have an exhaust leak or the cat is weak.

So there are a couple of considerations to think about. Now that I am thinking about it more I would check the timing issue first and see what Jackson's recommendations are.

If you have the CARB number I will look it up for you and see if the spec for timing is in there. Let me know if I can help!

 

Wow, in depth answers! Thank you!

By your name, I would expect you probably work at a smog station. I actually was looking at some of your older posts in hopes of finding a solution. So thanks for posting up, the information is great!

I went back to try and have tested, but no go as they had to check my Carb numbers (not sure what that all meant, but that is what he said). So I will have to miss some work and go on Monday (If I decide to go before the new cat).

Now for my ignorance in the testing process. I am pretty sure I have a leak between the cat and the Header. It just doesn’t seem to want to fit correctly. DC header, stock cat. But how does a leaking like that move my numbers up? I would have though that it would have just meant less flowing through the cat, and they wouldn’t have noticed unless they heard it, and at that point they would simply tell me to fix the leak. How does a leak like that effect the numbers?

I think my timing should be pretty close at this point, but from what your saying, combining the aggressive advancement and the fuel pressure still would not give me those numbers.

Does this mean its time for a new cat then, or is it just the leak?

 

try using sea foam, it really works

 

The motor was rebuilt from the ground up only a couple of years ago (2 or 3), new bistons etc etc, I dont think carbon build up is my problem. Thanks for the advise though, I have used it on my other high mileage motors!

 

About the exhaust leak...depends where it is located.

If it is before the O2 sensor it can mess up everything because the ecu will not be doing what it should. Not the case with your's.

Before the cat.. It can let to much O2 in and the cat will not heat up correctly and or flood the cat with O2 and basically just stop up the works would be the best way to put it. Which I think is your problem.

The cat needs a varied A/F ratio. The ecu see's what the O2 sensor is doing and keeps the mixture swapping from rich to lean etc... if the cat does not get the proper rich, lean, rich, etc... it will not be working like it was designed too.

Right now your cat is always lean because of the leak so this is a problem.

Now lets get back to what the tech was saying about your CARB numbers. What the CARB numbers are all about is that the parts were sent to the California Air Resources Board for testing and when they see that it doesn't raise the emissions they assign a CARB number to it and the part is now smog legal. Now the numbers are specific to the year, the motor, and the vehicle. Hope that shed's some light on that subject.

 

Thanks again!

I understand what carb numbers are, just didnt understand who the guy had to call to verify them. Seems weird that one guy barley even looked at them, then another guy had to call someone to check them out........

So, probally my issue is the leak. Any secrets to making this thing fit? I dont see why its not?

In truth I run a hollow cat most of the year. It seals up nice. Yes, I know Im, a bad person. Quite honestly, the car gets driven probally once every two weeks. This one seems to have the exact same ends on it, not sure why its not sealing up. Anyway, guess I will have someone do some grinding and welding and ill bolt it back on and see whats up.

Now for another question to you. Being that Im not from California, or even the USA, I am having a hard time understanding what I am supposed to do when my car fails. Do I still pay my registration, and once the car passes smog, they will send me new registration stickers? What happens if it hasent passed smog by the time the new sticker is needed? Do I still drive it?

Someone help me out here!

 

yeah, it's probably the leak.

And if the car doesn't pass smog you can take the failed report to the DMV and ask for an extension. You will have to pay the fee's associated with the initial registration and they will give you up to two months.

 

Wow, really? That might be the way to go as I am moving back to Canada, i can register it without doing smog first.

Thanks for the help!

 

just retard your timing a bit or run a bit richer, either way that will lower the NOx.

it occurs when the cyl temps get too high, usually from detonation or running lean. you even said u heard pinging. ding ding.

 

Did you read my first post?

"By looking at the numbers above, could I pass smog simply by increasing my fuel pressure to above 50Psi to cool the cylinders and retarding the dizzy timing?"

Thanks for the help SmogMan, Im going to see why the cat isnt fitting properly, hopefully problem solved.