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[Bojan]

So, I will probably need cats for my car.
At the moment, there are no cats installed (it is registered as LPG car, so no emission test, but probably will re-certify it as petrol user again).
I see that general consensus is that replacement-patern ones are crap.
Genuine are expensive and, as it seems, not availbale any more.

So, two questions:
1) has anybody found a suitable replacement cat (that is close to OEM one in terms of durability and sound)
2) second hand ones -> how to check if they are OK, if I find them?

PS. As the car is quite old (1996 V6) - can I use cats from 2.6/3.2? Its more likely to find them in good condition, as they are younger. I would cut the second cats, and transfer them to my downpipes.

[zirk]

Your probably better of fitting genuine second hand, 2.6,3.2 will fit and should work ok, might have to mess about with the Lambda holes, cant remember if a 1996 is dual or single sensor per cat.

Put a Wanted Ad up, theres probably more 2.6,3.2 kicking around as some have retro fitted 3.0 Cats to there late cars.

[zirk]

Out of interest did the LPG perform any better without Cats?, guessing it was a lot louder overall.

[frostbite]

I would say quieter, I have a friend with an lpg v8 disco and hey says it burbbles less aswell as minimal performance loss

[casared]

Cats for U I have had one on my Omega for four years sound as a pound

[omegod]

Which cats would you want, I have 2 of the larger cats off a 2.6 and the postage to Slovakia is looking surprisingly like  only £20

[Bojan]

Without cats, straight pipes welded in on their positions -> its somewhat louder, and there is a distinctive knocking sound when accelerating harder. Something similar to failed exhaust manifold gasket.
Also, low revs torque is affected a bit (it looses some of it).

Current setup is - small flow-trought mufflers welded on positions of cats -> better low revs torque, almost no exhaust knocking on acceleration. But as the mufflers are universal (no double skin or anything), the sound they create is not very nice. The car is quieter, but there is a bit of rattle from this mufflers on acceleration (not very noisy).

Hopefully, OEM or similar cats will give it a sound as it should be (no knock, no rattle).

Omegod - PM sent.

[Diamond Black Geezer]

That's good information for anyone wanting to fit straight-through's on an Omega V6.  I suppose in theory the engine could be timed/mapped to suit the straight-throughs, but then come MoT time (and fitting the cats just for the week of the test) the engine would be running like a bit of a pig, possibly thereby failing emissions.

Hope you get sorted soon Bojan 

[zirk]

That's good information for anyone wanting to fit straight-through's on an Omega V6.  I suppose in theory the engine could be timed/mapped to suit the straight-throughs, but then come MoT time (and fitting the cats just for the week of the test) the engine would be running like a bit of a pig, possibly thereby failing emissions.

Hope you get sorted soon Bojan 

De catting an LPG means, in theory, it should go through the MOT without issues, when presented to the Tester as an LPG as there are wider emission tolerances allowable for a LPG Fuel System, this is all subject to year, vehicle type etc.

Problem is, in practice, a lot of the Testers cant be bothered with it all, unless there used to LPG Testing, as it means getting the Reference Manuals, out, reading the Rules and Regs, adjustment of  Emissions Equipment Tester to suit blah, blah, blah.

[Nick W]

That's good information for anyone wanting to fit straight-through's on an Omega V6.  I suppose in theory the engine could be timed/mapped to suit the straight-throughs, but then come MoT time (and fitting the cats just for the week of the test) the engine would be running like a bit of a pig, possibly thereby failing emissions.

You could buy new cats for £70 per side and forget about them for the rest of the car's life.
Or is that too easy?


I wish I had replaced the O/S cat when I fitted the cat-back exhaust 2 years ago. Then the whole system would have been replaced from the cylinder heads out - I had changed the N/S cat when it broke up soon after changing the head gaskets.

[Kevin Wood]

That's good information for anyone wanting to fit straight-through's on an Omega V6.  I suppose in theory the engine could be timed/mapped to suit the straight-throughs, but then come MoT time (and fitting the cats just for the week of the test) the engine would be running like a bit of a pig, possibly thereby failing emissions.

Hope you get sorted soon Bojan 

De catting an LPG means, in theory, it should go through the MOT without issues, when presented to the Tester as an LPG as there are wider emission tolerances allowable for a LPG Fuel System, this is all subject to year, vehicle type etc.

Problem is, in practice, a lot of the Testers cant be bothered with it all, unless there used to LPG Testing, as it means getting the Reference Manuals, out, reading the Rules and Regs, adjustment of  Emissions Equipment Tester to suit blah, blah, blah.

If it is presented on LPG, they are obliged to test it on LPG. Problem is, 99% of LPG cars will pass the test with the default limits these days now that crude mixer systems are a thing of the past, so you'll have a fight on your hands arguing that you should benefit from the lower limits, especially when the tester notices you've binned the cats.

[Bojan]

To Nick W: 70£ per side? Pattern? If yes, how do they sound?

[Nick W]

To Nick W: 70£ per side? Pattern? If yes, how do they sound?

Quiet.


Fitting it consisted of undoing 5 bolts - two at each end, and the gearbox mount -, lifting the new one into place, and swapping the O2 sensor over.


Like any exhaust pipe, they are a consumable part, and should be treated as such.

[Bojan]

I'm concern because many people claim that pattern ones sound like crap.
I have been in battle with crapy sound (on v6 omega) for years, now the car has a reasonably good exhuast note, and really don't want another episode of 'crapy exhaust sound' drama.
What is the manufacturer/make that you've installed?