How much HC does CAT remove?
- Thread starter TurboHogg
- Start date
Now was that a reduction of 500-600ppm. If that is a reduction of 500-600ppm that will certinly solve my problem. This is where I am I scored a 312ppm and allowable is 220ppm so I am not very far from passing. I am triing to deside if I sould buy the CAT or Emissions chip. Thanks Tracy
Well, I did that comparison after developing my own emissions chip. Without the cat, I leaned out the chip and was able to get my HC down from over 1300 ppm to less than 500 ppm while basically leaving the co very low and not checking the nox. Then I put on the cat, checked it one more time, and went and passed the test. So far as I know, no one else leans out the chip when they make an emissions chip, they just adjust the idle speeds and fan on/off temps. How much to lean it out is different for every car (and Joe, our moderator, thinks these things are too lean already and that I shouldn't have seen the improvements that I did 
), so the two I've done I've done using an exhaust gas analyzer while burning chips. That's all a long-winded way to say that I doubt very seriously that just changing the chip is going to make your car pass. The way to think of the cat is that it removed about 97% of the hc, so in your case the 312 should go down to about 10 ppm. Get the cat, don't worry about the chip.
), so the two I've done I've done using an exhaust gas analyzer while burning chips. That's all a long-winded way to say that I doubt very seriously that just changing the chip is going to make your car pass. The way to think of the cat is that it removed about 97% of the hc, so in your case the 312 should go down to about 10 ppm. Get the cat, don't worry about the chip.
