Tuxblacray: She's Back In Black! Check out my pics @ My Link
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I am 51 and can say that I have seen cats "wear" out by the internals coming loose, causing blockage. I have also found the internal mesh (on the monolithic ceramic types) clogged. My solution is to use a large hammer drill to "clean" out the blockage and put the cat back in place. If you don't like the sound - get new mufflers - many great sounding cars were built in the 60s/70s without cats. I have always seen an increase in mileage and performance - even if it was only 1 or 2 mpg.
so many people here are having cats stolen off cars.
I had attest pipe I fitted on a l200 truck, made a lot more power. don't know about mpg,just drove it harder.
I have a friend with an 03 corolla with bad cat. and the cost to replace was over $1000, of course it has 270,000 miles one it. And I had a ford ranger that went bad about 140,000..so yes they do go bad, mine had to replaced....and the corolla is just blow out, so only problem is the check engine light stays one.
Several types of vehicles are PERMANENTLY EXEMPT from the E-Check test requirement and do not need a visual inspection. A complete list with a detailed explanation may be found in Ohio Administrative Code, Section 3745-26-12(c). It is not necessary for vehicle owners that are permanently exempt to be issued an exemption certificate. The most common types are listed below.
Since my car is older than 25 years and I have Collector plates, I qualify for permanent exemption under numbers 1 and 3.