Catalytic Converters - 6.0 V12
Moderators:davidr, BigCatXJS, dhdove
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DavidHarris
- Posts:2
- Joined:Fri Jan 04, 2008 6:23 pm
Help! The beast has failed its MOT on emissions and it looks horribly like the cats. Does anybody have any experience of refitting the down pipes and cats? a reliable workshop? or some suggestions for simply accessing the bolts at the downpipe/manifold flange?
Catalytic Converters - 6.0 V12
David,
Check the lambda sensors first. Much cheper to fix than a catalytic converter. They can easily cause a problem in idle CO levels. It's relatively to perform a voltage check on them or alternatively get a delaer or specialist to check them properly.
Good luck
Paul
Check the lambda sensors first. Much cheper to fix than a catalytic converter. They can easily cause a problem in idle CO levels. It's relatively to perform a voltage check on them or alternatively get a delaer or specialist to check them properly.
Good luck
Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)
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DavidHarris
- Posts:2
- Joined:Fri Jan 04, 2008 6:23 pm
Catalytic Converters - 6.0 V12
Paul,
Sorry for the late reply. I did indeed get the lambda sensors checked. They were fine. So, I've had to bite the bullet and get the cats replaced. The downpipes were fine and I didn't want to risk (nor could I afford!) the possibility of shearing bolts in the manifold, so I' had the double cats cut out and replaced with a single modern sports cat. I was a bit worried about the exhaust 'tone' but it's not much altered and if anything it's a bit sportier. The old cats had largely disappeared, there was precious little left. Which leaves you to think where the material has gone? Stuffing up the silencers down stream no doubt. Anyway a saga over. Thanks for your advise and interest.
Sorry for the late reply. I did indeed get the lambda sensors checked. They were fine. So, I've had to bite the bullet and get the cats replaced. The downpipes were fine and I didn't want to risk (nor could I afford!) the possibility of shearing bolts in the manifold, so I' had the double cats cut out and replaced with a single modern sports cat. I was a bit worried about the exhaust 'tone' but it's not much altered and if anything it's a bit sportier. The old cats had largely disappeared, there was precious little left. Which leaves you to think where the material has gone? Stuffing up the silencers down stream no doubt. Anyway a saga over. Thanks for your advise and interest.
Catalytic Converters - 6.0 V12
David,
Tks for letting us know how you got on. I suspect others may be interested in where you got the single cats, how much you paid and how difficult they were to fit. Well, I'm interested even if no-one else is!
Paul
Tks for letting us know how you got on. I suspect others may be interested in where you got the single cats, how much you paid and how difficult they were to fit. Well, I'm interested even if no-one else is!
Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)
Catalytic Converters - 6.0 V12
I was reading the other day about how you can cut out the old cat and weld a new one in. Seems there are more and more options these days which is a relief!
I had to replace the manifolds on my 4.0 which were cracked and manage to break the weld on the down pipe where the two go into one. This is a commom weak spot on the 4.0L. Luckily had a spare which I had bought and the car has just passed its MOT which tells me the 'used' cat is working well so was a bargain as I now have a spare cat.
I had to replace the manifolds on my 4.0 which were cracked and manage to break the weld on the down pipe where the two go into one. This is a commom weak spot on the 4.0L. Luckily had a spare which I had bought and the car has just passed its MOT which tells me the 'used' cat is working well so was a bargain as I now have a spare cat.
Catalytic Converters - 6.0 V12
Graeme,
I had the usual weld split on my car just before Littlewood in 2006. Driving it for the next three days caused quite a lot of interest from other road users, pedestrians and eventually the constabulary! By this point the pipe was completely split apart, but I got it sorted for £30 of welding. I might write something in the mag soon about this.
As regards the cats, I'm not sure that you can really assume they are functioning just because it passes the MOT. At least one specialist has told me that an AJ16 can pass a MOT without the cats there at all. The lambda sensors seem to be critical on an AJ16, but perhaps not the cats.
Paul
I had the usual weld split on my car just before Littlewood in 2006. Driving it for the next three days caused quite a lot of interest from other road users, pedestrians and eventually the constabulary! By this point the pipe was completely split apart, but I got it sorted for £30 of welding. I might write something in the mag soon about this.
As regards the cats, I'm not sure that you can really assume they are functioning just because it passes the MOT. At least one specialist has told me that an AJ16 can pass a MOT without the cats there at all. The lambda sensors seem to be critical on an AJ16, but perhaps not the cats.
Paul
1995 XJS 4.0 Convertible
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)
1980 XJ-S Pre-HE
Jaguar 4.2 Supercharged engine (but not with a Jaguar body..)
Catalytic Converters - 6.0 V12
When I was at the XJS seminar 2 years ago a couple of guys were talking about straight through exhausts. If the AJ16 can manage without them then this would be excellent!
I am sure an article on the exhausts would be of great interest - when I investigated stainless steel I discovered there is very little experience of the AJ16 exhaust and so the cost is significant. Mine though rusty is still solid after 12+ years so am hanging on for a while yet!
I am sure an article on the exhausts would be of great interest - when I investigated stainless steel I discovered there is very little experience of the AJ16 exhaust and so the cost is significant
. Mine though rusty is still solid after 12+ years so am hanging on for a while yet!
Catalytic Converters - 6.0 V12
Hi,
It look like my cats have gone, any thoughts about the best way to proceed?
Cheers
Jon
It look like my cats have gone, any thoughts about the best way to proceed?
Cheers
Jon
1977 Daimler Double Six Coupe
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kevinhafner
- Posts:53
- Joined:Sat Nov 01, 2008 6:53 pm
Catalytic Converters - 6.0 V12
Hi Jon,
How do you know they gone? Is it a bad reading of CO levels in which case it could also be the lamda sensors.
I recently managed to get one from Graham at Grublogger. There are also other companies that sell the matrix inside which can be fitted after neatly cutting open the box and rewelding after fitting.
If you manage to get one shine a torch in the end and sensor hole before fitting, just to make sure they are ok. They often blow in the back before they look bad in the front.
Regards, Kevin.
How do you know they gone? Is it a bad reading of CO levels in which case it could also be the lamda sensors.
I recently managed to get one from Graham at Grublogger. There are also other companies that sell the matrix inside which can be fitted after neatly cutting open the box and rewelding after fitting.
If you manage to get one shine a torch in the end and sensor hole before fitting, just to make sure they are ok. They often blow in the back before they look bad in the front.
Regards, Kevin.
Catalytic Converters - 6.0 V12
I think mine have already been cut once, can they be done again? The honeycomb on one has disintegrated and the shell of the other has cracked. Am i right in thinking that the 6ltr has 4 cats? 2 in line either side? is it possible to get away with 2? Which companies would be best to get it cut out and put back in?
Cheers
Jon
Cheers
Jon
1977 Daimler Double Six Coupe
Catalytic Converters - 6.0 V12
Further to this,
had little or no response sadly but have found a company willing to supply "OEM" cats at a reasonable price. The only issue being that as far a s i can tell from there web picture the pipes only have one cat per side and not the two as on my car. Is this ok? Would it still get though it's emissions ok for the MOT? I notice that on some of the USA websites that this is also the case for the later 95-96 cars.....
Please help, a very confused XJS owner!
had little or no response sadly but have found a company willing to supply "OEM" cats at a reasonable price. The only issue being that as far a s i can tell from there web picture the pipes only have one cat per side and not the two as on my car. Is this ok? Would it still get though it's emissions ok for the MOT? I notice that on some of the USA websites that this is also the case for the later 95-96 cars.....
Please help, a very confused XJS owner!
1977 Daimler Double Six Coupe
Catalytic Converters - 6.0 V12
In the end i went for both sides from onlineautomotive.com. The people who fitted them for me said they were complete buggers to fit and to my untrained eye look like they hang a little lower than the old. However they have the later style one cat per side so performance seems better and the sound with my Aj6 eng exhaust is lovely!
1977 Daimler Double Six Coupe
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