caytalytic converter issue?? 850glt

just returned from a 500 mile round trip down and back in one day to
south florida....on the trip back my pristine 96 850 with just over
107,000miles on the odometer seemed to develop a severe case of not able
to go over 70 mph on the interstate...if i pushed furthur down on the
accellerator, all it did was drop down a gear or two,make more noise and
take a long time to increase speed,maybe 5 mph...i am suspecting the
converter is partially blocking the exhaust...i noticed a slight
increase in temp reading on the gauge which seemed to be in sync with
the increased engine rpms...very hot today here in florida mid to upper
90's....wondering what the options suggested are for getting this back
on the beam....car is like new in all other respects....just doesn't
want to rev much over the 3000rpms easily.... also, cost is a
consideration...what happens ,not that i would do this, but what if a
"test" pipe was installed in place of the cat? are there generic cats
that fit right in? what is expected cost from a dealer?
looking for helpful suggestions here.....thanks in advance....if you
need additional info, drop me a line!

regards

 

Could be

...i noticed a slight

A long term test?

are there generic cats

Yes--$299 for my rabbit 8 years ago

what is expected cost from a dealer?

Arm, leg, kidney, 3 eyelashes and a pint of blood

Others might know better, but I would check the cost of an OEM one, and a
universal one.

Labor is not too bad unless the 02 sensor is in it

 

If the catalytic convertor is clogged and causing backpressure then
about the same thing will happen in any gear at higher RPMs. Try it in
first or second at the same high RPMs for a bit and see if it is
noticeable there- maybe on a hill.

Have the plugs been changed recently?

It could be something as simple as an anti-knock sensor reacting to a
bad load of gas and the hot weather, and it is retarding the spark
advance to compensate.

Maybe the timing belt slipped one notch?

I don't know the car enough, so these are just general comments, but
don't go blowing a wad on the catalytic convertor before being sure
that it is the problem.

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 240 Estate - '93 960 Estate

 

Simple question- is the "check engine" light lit? I can't remember
if that year has OBD2, but regardless, there should be some
diagnostic software built in that may help you with troubleshooting.

Like Randy said, replacing a catalytic converter (new one or straight
pipe) is a lot of work to eliminate just that one possibility.
Checking and maybe replacing old fashioned tune-up items (plugs,
wires, distributor, vacuum hoses, clean throttle body) might be a
better bet.

Random thought, are you running premium or regular gas (admittedly
mine runs fine on regular, even on hot days in Florida)?

 

I don't know how it's set up on an 850 but on the older cars there's a
flange so you can just disconnect the cat for testing purposes. Noisy as
heck, but you only have to drive down the street and back.

 

I think a bad O2 sensor can cause high-RPM stumbling and misfiring.
But I think it would set some computer error codes, too.

 

On my 98 s70, which sure looks to be very "similar", I will be doing a cat
soon. I have researched an aftermarket as the original part price is close
to a $1000, part only, and no o2 sensors which may or may not be needed.

If you need one, there seem to be at least 3 choices. All the ones I
have found any info on are made with steel that has an aluminum finish,
then welded. Welding removes the aluminum finish, makes me wonder why they
bother. Depending where you live, I would expect a life of 3-6 years, it is
just a guess. Costs about 300-400 dollars for the part. As I say, I have
not done it yet. Metal thinkness seems to vary from 0.075" to 0.060"
depending on the manufacturer. I have decided to get the one made by D.E.C.
in California (D.E.C., 15125 Califa St. Unit C, Van Nuys, CA 91411 (818)
994-1908 ) I have no relationship with d.e.c. I just expect that their
product will fit properly, and work properly, and have been told they use
the thicker steel. I will be replacing mine for rust through reasons, so I
prefer the thicker steel.

Some people claim that the aftermarket cats can cause problems with codes,
I assume from o2 sensors. The folks at d.e.c. claim to have the o2 sensor
depth in the gas stream at the same depth, and also the same locations as
the original.

Make sure you need a cat before you get one. If yours shows any signs of
porisity or flacking (or holes) where the welds are that hold the internal
structure to the exterior structure you will need one soon, If you have
holes you should have codes that would point to the o2 sensors, which may
not be the problem at all. With holes you should address the situation
asap.

The other option is to get a used original part from a yard. I chose not to
go this way as the yards that have them want almost what a new aftermarket
will cost.