'91 940 Cat Replacement Pipe

Hi
My cat on my 940 has blown a hole right near the weld, I haev patched it
with Gun Gum how ever it keeps blowing it out after a week or so. Does
anyone produce a cat replacement pipe? Would it be legal to remove the
cat and replace with a staright through pipe?

I am in the UK.

Thanks

Simon T

 

Euro car parts sell a pattern cat for about £80. (www.eurocarparts.co.uk)

Probably, depends on the year.

 

It would not be illegal to remove the cat and replace it with a straight
pipe as your car was made before the cat became a UK legal requirement. Does
your car have an Oxygen sensor mounted at the front of the cat? If so you
will need to keep the cat body but rod it through so that the elements,
which are obviously clogging up, will no longer present any back pressure.
You will gain about 10 bhp as a result.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

Thanks for that Info Peter, where on the cat would the oxygen sensor be
located? Front of the cat, between the cat and the bodywork?
When you say rodding it, you mean forcing a sizeable bar into the cat?

If I dont have an oxygen sensor I can replace with a normal pipe, any
ideas where I could purchase one of these in the UK?

Many Thanks

Simon T

 

Volvo UK on their early 1990 models which were available from new
registrations in August 1989 until about Feb 1990 offered a NON Lambda Sond
CAT retrofit free of charge to their 740's because Volvo had not got the
Lambda Sond system working and available until early 1990. (remember the
adverts in th press 'Every Volvo can now have a cat').

For anyone who got one of these retrofits will have found out, whet it came
time to replace the exhaust boxes south of the CAT (the cat was stainless
and the front pipe was fine) they found that, surprise surprise, the genuine
volvo exhaust parts were very expensive indeed. This was because the
retrofit system Volvo punted out was a hybrid one off. The front pipe was a
one off in length, the box between the differential and the CAT was a one
off and the CAT itself was also an odd size. So all you could replace was
the up an over pipe and the rear pipe. I could not find an after market
supplier either (guaranteed to fall apart specialists 1 month after the
guarantee expires). Great.

As volvo offered a complete system for older cars (the front pipe from the
manifold was excluded so had to be bought seperately but I was able to beat
Volvo up a bit on price) at a discounted price it was cheaper to ditch a
perfectly good CAT and front pipe and replace the whole lot.

I replaced the lot Manifold to tail pipe and I also expected an increase in
performance but also not. Don't know why and nor did Ovlov. I did not have
to make any adjustments to the feul or ignition system because all I was
doing was putting the car back into its pre retro format.

I was wondering what condition the rest of your exhaust system is in because
I suspect that the length of the CAT (even yours not being the interim Volvo
botch) will not be the same length as a non cat verson (and hence nor will
the attached pipes/boxes). Maybe you could ask this queston ov Volvo. It
would be interesting to see if they actually know.

The CAT became mandatory in the UK in 1993 (not sure of exact month) so you
will have no problems on that score. However it seems to me that the Lambda
Sond and computer thingi will be trying to meter and set your feul mixture
(and whatever else it does) on the basis that a CAT is present. Will this
cause an issue - might do. Can you disconnect the Lambda Sond - don't know,
will it work even if you can - I would have doubts - perhaps Volvo technical
would know for sure.

One last point, is it worth buying a genuine Volvo exhaust or wacking on a
Bosul/Ti/Walker thing from a quickfit place. My experience has been YES,
absolutely no question. First it has always been fitted properly by Volvo
with new mounting rubbers all included in the price. Second for older
Volvo's Volvo UK have offered a complete system (ex front pipe which hardly
ever goes anyway) at a substantial discount to the sum of the parts - check
it out. Third our 740 was new in Sept 1989, using fingers I make that now
15 years old. I put the second replacement on last year so we are averaging
7 years a pop. Fourth, the Bosul/Ti/Walker boxes that are generally
available in the UK will last 3 to 4 years (if you specify the 3 yr warrenty
version) and the tail and up and over axle pipes a bit earlier - you try and
get a replacement under warrenty at 2 1/2 years.

Andy

 

Andy that would be 1993 Model Year, that is August 1992, that the cat became
legal in UK, not just for Volvo but ALL cars.

 

BRILLANT then the mufflers will be filled up with the catalitic converters
broken pieces .Beside do you have any respect of why the converters there
?Its there to clean the emissions of your car to help protect our enviroment
which is in a mess with out any help from such 8unwise illegal advice .

 

Did I say the cat could be rodded in place? Try using your brain before
leaping in to castigate people who may well know a bit more than you about
the situation. Do you have any knowledge of the UK requirements for
catalysers?

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

Been away for the weekend - Notting Hill Carni - oh yes, nice sunshine and
listened to radio as we beat the Aussies. I duly doff my cap to you Peter
but I trust most of what I wrote was accurate and getting the date wrong
won't actually effect the rest of my response to Simon.

Andy

 

Andy, hope you enjoyed the Carnival, it was a bit grey and murky down here,
so I didn't venture outside for long. Great cricket news indeed. My addendum
was not intended as criticism merely to round out your explanation and
include ALL cars from that date.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).