General question about passing emissions test
02-11-2018, 03:14 AM
#1
Staging Lane
Thread Starter
General question about passing emissions test Since I'm installing LTs, 3" ORY and new pipe all the way back, im going to need to install cats for emissions. I didn't buy a catted Y because I didn't need them where I used to live. My question is will 1 cat installed after the ORY clean the exhaust enough to keep the CEL away, or will I need 1 cat on each side of the y-pipe? And then O2 sensors installed as well. I also need to pass a sniff test, so not only do I need to keep the CEL away, it still has to be clean enough to pass the sniff test. This is just a general question about how efficient a catalytic converter is, and if an LS1 with 68k miles should have 1 or 2 to pass emissions testing. I know there is 2 from the factory, but...... You know....
02-11-2018, 06:06 AM
#2
TECH Fanatic
Does Denver Colorado have a visual test to see if all emissions equipment is installed? If yes, your car will likely fail for lacking a second O2 sensor. If no visual test is required, the O2 sensor after the cat can be deleted from the wiring and more importantly, the programming (aka your "tune") inside your powertrain control module (PCM). This deletion will prevent that missing O2 sensor from illuminating the Check Engine Light.
As to the rest of your question, I don't know. This might be tune dependent inside your PCM.
Rick
As to the rest of your question, I don't know. This might be tune dependent inside your PCM.
Rick
02-11-2018, 01:07 PM
#4
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As I mentioned in your other thread, none of this matters if there is a strict visual. If you move the cats from their factory location (which is what happens with ANY LT header for these cars), then it's not emissions legal, period. However, many states don't do a visual, or at least not a thorough visual, so this may not matter. But, if CO looks for this, then it won't matter how many cats or O2 sensors you have, nor how "clean" the exhaust is. You will fail the visual, and that will be that.
So, first order of business is to find out what sort of inspections they do during the test. I'm going to lock this one down since you already have a second thread going on this in the regional section, which is more appropriate as you'll need info from other CO members.
So, first order of business is to find out what sort of inspections they do during the test. I'm going to lock this one down since you already have a second thread going on this in the regional section, which is more appropriate as you'll need info from other CO members.