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notfarnow notfarnow is offline
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Join Date: Aug 2004
Location: New Brunswick, Canada
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Quote:
Originally Posted by speeder View Post
I realize that they get plugged and can affect performance, my question was "how can you tell when it's getting plugged?" It might be easy to tell if one is completely plugged, but how about only partially?

When the cat plugged on my '96 jetta, I could barely see through it when I held it against the light like an air filter. I'm guessing you're not looking to take yours off though. Pressure gauges, I guess.

I've seen manuals that show a pressure gauges before & after the cat. That makes sense.

Quote:
Originally Posted by speeder View Post
The O2 sensor question is a separate issue. What will a bad sensor (or 2) do? Do they affect mixture all through the rpm range, such as under light acceleration?

New cats, or even used ones, are very expensive and not the kind of thing that I would change just for the *why not* of it. Same w/ sensors, I'd need minimum (2) @ ~$150 each. I need to know how to diagnose them.
When the O2 sensor was bad on dad's Carrera, it ran rich ALL THE TIME. Gassy idle and even smelled rich underway, if you caught a whiff of the exhaust (cabrio). The Bently has a set of voltage values it should giving with the engine warm, it was way off. Took 15-20 mins to test, and another 15 to change it.

I'm sure the same info would be out there for the 996
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Last edited by notfarnow; 10-31-2008 at 10:06 AM..
Old 10-31-2008, 09:54 AM
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