mgbeda
Active Member
Hi folks,
I fairly recently got an '87 Fifth Avenue with about 115,000 miles on it. A variety of symptoms made me think that I had one or more clogged cats. Long story short, I dropped the exhaust system, and I "tested" the cats by taking my shop vac, setting it up to blow, and sticking the hose in the top of the Y pipe (it's almost a tight fit). Well, to my surprise, when I blow down one end of the Y-pipe I get a nice breeze coming out the other end. And when I blow down either end of the Y-pipe I also get a nice breeze coming out of the tailpipe. At no point does the vacuum sound like it's straining against pressure.
So did I really just prove that my cats aren't clogged, or is there something more subtle I'm missing, like just a little bit of cloggedness causes a big hit in performance?
If the cats really aren't clogged that's halfway great because I didn't know how I would replace them (and I live in CA so they would have to be replaced, unless I sell it to my brother in Cleveland). But it also halfway sucks, because it means I wasted a LOT of time and effort.
Thoughts?
I fairly recently got an '87 Fifth Avenue with about 115,000 miles on it. A variety of symptoms made me think that I had one or more clogged cats. Long story short, I dropped the exhaust system, and I "tested" the cats by taking my shop vac, setting it up to blow, and sticking the hose in the top of the Y pipe (it's almost a tight fit). Well, to my surprise, when I blow down one end of the Y-pipe I get a nice breeze coming out the other end. And when I blow down either end of the Y-pipe I also get a nice breeze coming out of the tailpipe. At no point does the vacuum sound like it's straining against pressure.
So did I really just prove that my cats aren't clogged, or is there something more subtle I'm missing, like just a little bit of cloggedness causes a big hit in performance?
If the cats really aren't clogged that's halfway great because I didn't know how I would replace them (and I live in CA so they would have to be replaced, unless I sell it to my brother in Cleveland). But it also halfway sucks, because it means I wasted a LOT of time and effort.
Thoughts?