Just Got Back From Smog Test, and...
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
Just Got Back From Smog Test, and...
... was shocked to see that I barely passed on the HC test!
On the NO portion, I blew away the numbers. Max allowance was 430, average was 16-18, but I nailed a big fat 0!
On the CO portion, Max was .50, average .01, and I easily passed with .06.
However, on the HC portion, the Max was 54, average was 4, and I squeaked by with a huge 53! What the...?
My only mods are a cat-back system, a Halltech Stinger, and a custom-tune to match my mods.
However, right before the test, I put my stock airbox back on, and went straight to the smog center, which was only 2 miles from the house. Could that have been the culprit? Car NOT hot, hot, hot, and not much time for the computer to adjust for the lower volume of air with the stock box, so it was running slightly rich?
I spoke to the tuner about the results of the smog test, and what affect his tune might have had in that regard, and he said there was no way his tune would've caused me to barely pass the HC test. He said, in fact, if anything the the tune would make things burn much more efficiently.
Thoughts?
On the NO portion, I blew away the numbers. Max allowance was 430, average was 16-18, but I nailed a big fat 0!
On the CO portion, Max was .50, average .01, and I easily passed with .06.
However, on the HC portion, the Max was 54, average was 4, and I squeaked by with a huge 53! What the...?
My only mods are a cat-back system, a Halltech Stinger, and a custom-tune to match my mods.
However, right before the test, I put my stock airbox back on, and went straight to the smog center, which was only 2 miles from the house. Could that have been the culprit? Car NOT hot, hot, hot, and not much time for the computer to adjust for the lower volume of air with the stock box, so it was running slightly rich?
I spoke to the tuner about the results of the smog test, and what affect his tune might have had in that regard, and he said there was no way his tune would've caused me to barely pass the HC test. He said, in fact, if anything the the tune would make things burn much more efficiently.
Thoughts?
Le Mans Master
Joined: Feb 2006
Posts: 5,488
Likes: 4
From: USA
... was shocked to see that I barely passed on the HC test!
On the NO portion, I blew away the numbers. Max allowance was 430, average was 16-18, but I nailed a big fat 0!
On the CO portion, Max was .50, average .01, and I easily passed with .06.
However, on the HC portion, the Max was 54, average was 4, and I squeaked by with a huge 53! What the...?
My only mods are a cat-back system, a Halltech Stinger, and a custom-tune to match my mods.
However, right before the test, I put my stock airbox back on, and went straight to the smog center, which was only 2 miles from the house. Could that have been the culprit? Car NOT hot, hot, hot, and not much time for the computer to adjust for the lower volume of air with the stock box, so it was running slightly rich?
I spoke to the tuner about the results of the smog test, and what affect his tune might have had in that regard, and he said there was no way his tune would've caused me to barely pass the HC test. He said, in fact, if anything the the tune would make things burn much more efficiently.
Thoughts?
On the NO portion, I blew away the numbers. Max allowance was 430, average was 16-18, but I nailed a big fat 0!
On the CO portion, Max was .50, average .01, and I easily passed with .06.
However, on the HC portion, the Max was 54, average was 4, and I squeaked by with a huge 53! What the...?
My only mods are a cat-back system, a Halltech Stinger, and a custom-tune to match my mods.
However, right before the test, I put my stock airbox back on, and went straight to the smog center, which was only 2 miles from the house. Could that have been the culprit? Car NOT hot, hot, hot, and not much time for the computer to adjust for the lower volume of air with the stock box, so it was running slightly rich?
I spoke to the tuner about the results of the smog test, and what affect his tune might have had in that regard, and he said there was no way his tune would've caused me to barely pass the HC test. He said, in fact, if anything the the tune would make things burn much more efficiently.
Thoughts?
and running rich didn't help your cause either.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
What did you mean by the running rich statement, too? Did you mean you think that I should've given the car more time with the stock air cleaner back on, so the computer could adjust itself to the lower air volume condition, or do you think the computer does not need time to adjust?
Safety Car
Joined: Sep 2003
Posts: 3,692
Likes: 5
From: Hayward CA
Your car was tuned for the Halltech. They have a tendency to make the car run lean....so the tuner probably richend the mixture a bit. Putting the stock airbox on would cause the car to run even richer, because it's not getting as much air as if the Halltech were on there.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
Your car was tuned for the Halltech. They have a tendency to make the car run lean....so the tuner probably richend the mixture a bit. Putting the stock airbox on would cause the car to run even richer, because it's not getting as much air as if the Halltech were on there.
Maybe a professional tuner will be nice enough to chime in here to confirm one way or another.
Safety Car
Joined: Sep 2003
Posts: 3,692
Likes: 5
From: Hayward CA
That's exactly what I thought when I installed a Halltech - the computer should be able to compensate...... WRONG. It was so lean it set off the CEL (I had to get a dyno tune). This leads me to believe the computers range is not a broad as it's believed to be
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
So, if it is what you suspect, then how are YOU going to get smogged? I guess I was extremely lucky. Is everyone else going to be that lucky if they got a custom tune AFTER fitting their after-market CAIs?
I guess this is where I wish I had gotten a Predator or something similar instead, so I could go back to stock for a smog.
I guess this is where I wish I had gotten a Predator or something similar instead, so I could go back to stock for a smog.
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Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
From the desk of Jim Hall (on what to do after installing a Halltech Stinger):
Note the first sentence. I think that is the key.
Here's how my C5 did after swapping out the Halltech for a Z06 box:
Allow 25 miles of driving to provide relearn time for the PCM> All fuel trims will eventually retrim to 14.7:1 except WOT. That will be leaner, but still well within the power range and will likely provide 5 to 6% more torque and horsepower throughout the rev band.
Please understand that new air will not cause your car to run lean. The factory air fuel ratio is 12.3:1 for Wide Open Throttle, which is way too fat for max power. Our intake does not need programming to operate properly, but will see added benefits from a good LS1 Edit program.
Please understand that new air will not cause your car to run lean. The factory air fuel ratio is 12.3:1 for Wide Open Throttle, which is way too fat for max power. Our intake does not need programming to operate properly, but will see added benefits from a good LS1 Edit program.
Here's how my C5 did after swapping out the Halltech for a Z06 box:
Drifting
Joined: Oct 2002
Posts: 1,774
Likes: 66
From: SoCal
It takes time for the computer to re-adjust to the stock intake. Driving 2 miles isn't enough. So that would play a part in it. Also if you started the car and drove 2 miles and got it smogged the CATS didn't get the chance to get hot. Whenever I go for a smog test I run it down the freeway for awhile and get the CATS good and hot. Then I take it in for the smog. Passes with low numbers across the board. Took the ZR1 in earlier this year and the smog tech was amazed at the numbers that came out of that car since it was 17yo and high mileage.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
I noticed in 2007 your HC ran upwards, too, after returning from the Halltech to the ZO6 box, but did not get quite as high as mine, possibly due to you going to a much better breathing box than the one that came with your car. If I remember correctly, your car is my car's twin, down to the color and options.
I know from earlier communication with you, you said you swap to a factory box 1 week prior to your tests, while I had forgotten about that and didn't even go for a freeway drive.
Maybe in two years when I smog again, I should do the same. What do you think if for good measure, right before the test I also remove the filter element altogether, so the car gets even MORE air than stock, which would make it closer to the open Warhead element? Sure, there'd be no element for filtering, but I can't see how it can hurt anything to run no element for 4 total miles, especially since I still have closed fog shrouds, and my MAF is a screened one.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
It takes time for the computer to re-adjust to the stock intake. Driving 2 miles isn't enough. So that would play a part in it. Also if you started the car and drove 2 miles and got it smogged the CATS didn't get the chance to get hot. Whenever I go for a smog test I run it down the freeway for awhile and get the CATS good and hot. Then I take it in for the smog. Passes with low numbers across the board. Took the ZR1 in earlier this year and the smog tech was amazed at the numbers that came out of that car since it was 17yo and high mileage.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Dave,
I noticed in 2007 your HC ran upwards, too, after returning from the Halltech to the ZO6 box, but did not get quite as high as mine, possibly due to you going to a much better breathing box than the one that came with your car. If I remember correctly, your car is my car's twin, down to the color and options.
I know from earlier communication with you, you said you swap to a factory box 1 week prior to your tests, while I had forgotten about that and didn't even go for a freeway drive.
Maybe in two years when I smog again, I should do the same. What do you think if for good measure, right before the test I also remove the filter element altogether, so the car gets even MORE air than stock, which would make it closer to the open Warhead element? Sure, there'd be no element for filtering, but I can't see how it can hurt anything to run no element for 4 total miles, especially since I still have closed fog shrouds, and my MAF is a screened one.
I noticed in 2007 your HC ran upwards, too, after returning from the Halltech to the ZO6 box, but did not get quite as high as mine, possibly due to you going to a much better breathing box than the one that came with your car. If I remember correctly, your car is my car's twin, down to the color and options.
I know from earlier communication with you, you said you swap to a factory box 1 week prior to your tests, while I had forgotten about that and didn't even go for a freeway drive.
Maybe in two years when I smog again, I should do the same. What do you think if for good measure, right before the test I also remove the filter element altogether, so the car gets even MORE air than stock, which would make it closer to the open Warhead element? Sure, there'd be no element for filtering, but I can't see how it can hurt anything to run no element for 4 total miles, especially since I still have closed fog shrouds, and my MAF is a screened one.
I would simply install a new factory or Fram air filter and drive the car at least 25 miles after doing the swap. On the day of the smog test, I always take my car on the highway for 10 miles or so to get that cat really hot. I think it's a good idea to avoid running the car with no filter.
The thing that really bothers me is the fact that the "MAX" HC is being lowered. Our cars don't get cleaner with age, so why would the CARB reduce the MAX numbers? That is not rational, IMO. What's next - 20PPM of HC MAX???? It looks like there is a bureaucratic conspiracy in plan to rid all "older" vehicles from the streets by the time they are 10 years old. We need to fight this idiosy, don't you think?
BTW, I feel sorry for anyone with a bigger cam than stock, since there is precious little room for any more unburned fuel in that MAX HC spec!
Dave
Drifting
Joined: Oct 2002
Posts: 1,774
Likes: 66
From: SoCal
So, you're of the opinion then that glowing cats function to reduce HC better than cooler cats? Although ambient temps today were in the low 90s, I take it you mean get the car HOT, like they would get when you get on it for awhile, unlike how my car was probably just barely warmed up?
But you passed anyways so all is good.
Drifting
Joined: Oct 2002
Posts: 1,774
Likes: 66
From: SoCal
The thing that really bothers me is the fact that the "MAX" HC is being lowered. Our cars don't get cleaner with age, so why would the CARB reduce the MAX numbers? That is not rational, IMO. What's next - 20PPM of HC MAX???? It looks like there is a bureaucratic conspiracy in plan to rid all "older" vehicles from the streets by the time they are 10 years old. We need to fight this idiosy, don't you think?
Dave
Dave
Intermediate
Joined: Nov 2006
Posts: 27
Likes: 0
From: Napa CA
The thing that really bothers me is the fact that the "MAX" HC is being lowered. Our cars don't get cleaner with age, so why would the CARB reduce the MAX numbers? That is not rational, IMO. What's next - 20PPM of HC MAX???? It looks like there is a bureaucratic conspiracy in plan to rid all "older" vehicles from the streets by the time they are 10 years old. We need to fight this idiosy, don't you think?
Dave
Melting Slicks
Joined: Nov 2004
Posts: 2,275
Likes: 6
From: Lake Oswego, Near Portland Oregon
Dave, don't get me started on the Calif Air Resource Board (of Idiots). That is exactly the plan. I own a 1977 Triumph roadster that was manufactured to meet the 1977 emissions standards and still would (85K miles on the odo). CARB has continued to reduce the allowable emissions to a level that this car was never designed to meet. It has EGR, AIR pump, a new Toyota cat and still flunked CO. It's parked.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
Yes. Drive the car awhile and get the car up to temp and get the CATS hot. I took my truck in once from dead cold and drove a mile to the smog station. It barely passed. All stock and 4 years old (55k miles). Smog tech told me himself you should take it out for a drive first and get the CATS hot. They don't function fully until they do. I'm betting if you had drove the car for a bit to get the computer in sync with the intake change as well as getting the CATS hot it would have done better. But I an sure you were running rich.
But you passed anyways so all is good.
But you passed anyways so all is good.
I think our collective suspicions on the cold CATS and time to re-learn thing is what must have caused the super-high HC readings.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
And, I look too old to be trying to skate on being a college student from out of state. 