r2000swler@hotmail.com wrote:
> Got a phone call from a friend who is looking to buy a used 1990 Civc
> with 100K.
> MT and the car has been well maintained. The seller says the cat
> converter is
> "going bad and the exhaust is blowing by the converter".
>
> I doubted that even being posible unitl I looked at my service manual.
> I see that the
> exhaust manifold goes to " EX pipe A" which connects to "MIDDLE EX
> PIPE" which
> is fastened to the cat converter with a set of bolts that are spring
> loadd.
>
> Could exhaust gas bypass a clogged converter in this manor?
>
> I will be taking a look at this car Friday afternoon and thought I
> would ask if anyone in
> the group has seen this before. My first thought was the gasket had
> failed, or the middle
> exhaust pipe had cracked. I haven't done any work that far up the
> exhaust train since I
> quite ridding motorcycles. Seeing a set of spring loaded bolts holding
> the converter to the
> middle exhaust pipe surprised me.
>
> I plan using a longish tube to listen for the leak to pin point it. I
> don't think it wise to try to
> feel for hot exhaust gasses.
>
> Terry
>
if the cat really is clogged, i'd be beware of buying the car because it
will either have had a serious injection problem /or/ will have spent
its whole life pottering about on 3 mile journeys where the engine never
got hot. both scenarios wreck a motor pdq.

otoh, it may be just a blowing exhaust, in which case, it's easily fixed
and the problem goes away. inspection will reveal all.

and if your friend still wants to take their chances on whether the
motor was in 3 mile heck, make sure the easy things are fixed like
ignition, o2 sensor, etc., change the oil, makes sure there are no
coolant leaks, /then/ take the car on a good hard run on some nice steep
hills. red line, full throttle. that will burn out a bunch of the
accumulated carbon from the engine and the cat. you'd be amazed how
much better it can be after a couple of hundred miles of running at
"full working temperature".

then change the oil again.