I thought I would post this for anyone in the future. For several years I have failed my emissions test, and used to get by with a conditional pass. this year I pickup up a used MAC hi-flow H-pipe with cats for ebay for just over $100. It made a huge difference in the results and my car passed with flying colors. I'll post the old and new results so that if your concerned about whether an h-pipe will help you can see for yourself. I couldn't find any actual test results when I was deciding whether or not to purchase a catted pipe.
Here are my actual test results:
40 km/h test
------ limit / no-cats / MAC with cats
hc / 66 / 135 / 25
co / .37 / .65 / 0
no / 757 / 1232 / 404
Curb Idle test
------ limit / no-cats / MAC with cats
hc / 200 / 576 / 15
co / 1 / .87 / 0
As you can see the cats made a huge difference. Absolutely no CO%.
Here are my actual test results:
40 km/h test
------ limit / no-cats / MAC with cats
hc / 66 / 135 / 25
co / .37 / .65 / 0
no / 757 / 1232 / 404
Curb Idle test
------ limit / no-cats / MAC with cats
hc / 200 / 576 / 15
co / 1 / .87 / 0
As you can see the cats made a huge difference. Absolutely no CO%.