Quote:
Originally Posted by Cd
My little pea brain thinks that if you have a hole in your exaust ( for example - just a hypothetical example let's say " half the size" of your exhaust pipe, that would mean that your readings would be 50% cleaner than if you plugged the hole because half of your emissions are spewing out the hole.
Right ?
Concerning the hole in my exhaust, it was just in front of the muffler, and around 1/8 " X 1.5" .
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The test equipment takes a small sample of the exhaust gasses and calculates (an)
emission ratio(s). eg Hydrocarbons in
part per million.
If half of emissions are lost out a hole, but absolutely no ambient air is introduced (exhaust pressure > ambient air pressure) by the hole - up stream of the sample taken by the machine, the emission ratios will not changed. Of course exhaust pressure isn't all that high and with a hole half the size of the exhaust pipe some ambient air would surely be introduced - causing emissions ratio readings below what the car is actually producing.
A 1/8" x 1.5" hole in front of the muffler might have some small quantifiable effect on emission readings, but my best guess would be none. If your emissions readings were anywhere but the high end of the acceptable range, Bubba may well have simply decided that his time was better spent else where. (That presumes that the equipment allowed him to retrieve your previously stored readings? If so, I'd guess that it would only allow him to do that provided the VIN and/or registration number of the tickets matched.) Back in the late '80 early '90 in California, doing something like that would have put Bubba's inspector's certificate in jeopardy. Maybe Texas is more lenient? My earlier statement that they were required to redo the test was a surmise.
Your car failed because there was a hole in the exhaust.
Was it an emission issue? With a 1/8" x 1/5" hole, possibly.
Was it a safety issue? Maybe not at that instant. If your car doesn't have holes in the floor boards, you're pretty safe from carbon monoxide poisoning. On the other hand the hole will only get larger. Eventually (easily less than a year with short trips in a humid climate - parts of Texas) you have a loud, very leaky exhaust system that's prone to depositing large, nasty chunks of debris on the freeway. "Very leaky" and "debris" are both safety issues.