Long Tube Headers and Emissions
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Long Tube Headers and Emissions
I have an 05 SS and am wondering about emissions in CA. I have header mixed things about whether or not long tube will pass emissions. I have heard that they will not pass the sniffer or a visual, and I have also heard that long tubes should be able to pass a visual no problem and also that long tubes will pass the sniffer just as long as your o2 sensors are working properly and you have cats. Is any of this info true? Is there a place I can get the actual rules or regulations for emissions in CA? Thanks.
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you do need cats to pass a sniffer. I dont know if u can pass a visual or not, specially if they get under and see no cats. Here in AZ I dont know how well they do a visual but Im gonna find out. My manager at work was tellin me u can have a section of pipe removed for a cat and a piece of pipe fitted with flanges so u can put the cat in and go to emissions then take it right out if ya want. Somethin I never thought of and thought was pretty good of an idea
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I'm going to keep the cats. For me its just a matter of whether or not it will pass cause when I do have to go to smog I dont want to have to fail and or take off the headers and keeping switching them in and out.
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I don't agree with the rules, but they state the the factory catalytic converter(s) must remain intact and in the factory position(s). The converter are so far forward on our trucks that there isn't room for long tube without breaking that rule.
The reason the rule exists is so that cold-start catalyst light-off is not delayed by the additional exhaust tubing length between the heads and converters. Also, the oxygen sensor has to be in the flow post-collector. Long tube headers require that the sensor be moved further downstream since the collector is further downstream. The further from the head ports the oxygen sensor get the more "lazy" they get since they're measuring the output from operating conditions "too old". Basically you end up with bad data and that affects emissions too.
So, YES - long tube headers absolutely fail visual inspection by definition. All headers legal in California must have a California AQMD Expemtion Order number (EO#). I think this can be a plate welded on the primaries, numbers stamped in, or a sticker for the radiator shroud/core support.
Long tube headers themselves have minimal effect on actual emissions, the problem is the latency induced by the greater exhaust gas travel to the O2 sensors. Generally, they WILL pass the sniffer because there is very little affect at constant sustained throttle conditions where these test take place at on t he dyno.
Of course, legal headers must acommodate all factory emissions eguipment like EGR, A.I.R., O2 sensors, etc.
That's about all I know about this...
The reason the rule exists is so that cold-start catalyst light-off is not delayed by the additional exhaust tubing length between the heads and converters. Also, the oxygen sensor has to be in the flow post-collector. Long tube headers require that the sensor be moved further downstream since the collector is further downstream. The further from the head ports the oxygen sensor get the more "lazy" they get since they're measuring the output from operating conditions "too old". Basically you end up with bad data and that affects emissions too.
So, YES - long tube headers absolutely fail visual inspection by definition. All headers legal in California must have a California AQMD Expemtion Order number (EO#). I think this can be a plate welded on the primaries, numbers stamped in, or a sticker for the radiator shroud/core support.
Long tube headers themselves have minimal effect on actual emissions, the problem is the latency induced by the greater exhaust gas travel to the O2 sensors. Generally, they WILL pass the sniffer because there is very little affect at constant sustained throttle conditions where these test take place at on t he dyno.
Of course, legal headers must acommodate all factory emissions eguipment like EGR, A.I.R., O2 sensors, etc.
That's about all I know about this...
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So since I'm worried about the emissions issue your saying to stay away from the LT's right? The Bassani mid-length headers will pass emissions right? Thanks for the information too.
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They took a little more cutting and welding than the directions stated but once they were on everything works great. The Doug’s look like the collectors are farther downstream and they will clear the 4L80E. Check out Jegs or keep searching the classifieds here.
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