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[gbh]

Well I was out fitting the sidelight bulbs as MOT due this month and as the engine was running just popped around the car checking lights etc and thought oh the engine is misfiring but then thought maybe the exhaust is blowing and sure enough it is.Rather a nice rust hole come slot almost on the back box joint but mid section and as the other side was also looking a little rusty about the same place thought I'll phone around for replacing the back half.A very quick look on the internet revealed a price of around £100 for parts so then I thought let's phone around the local fitters and see what prices they come back with.First up KWIK FIT and their price was a not insignificant £380 glad I was sitting down and then another with £325 and finally and old school friends garage quoted £260 for a WALKER'S exhaust with a 3 year guarantee.Just wondered on your thoughts on the prices and quality of exhaust as not chosen yet and I may get under car tomorrow to see if it's worth patching with some sort of bandage!!!

[gbh]

And haven't asked but as I own a 2.6 Elite est any benefit in fitting a 3.2 exhaust? or is it the same?

[addy]

Have used TTM on ebay. Not too bad on price, seem well made and reasonable delivery time.

https://www.ebay.co.uk/sch/i.html?_sop=15&_osacat=0&_odkw=vauxhall+omega+2.6+exhaust&_from=R40&_trksid=m570.l1313&_nkw=vauxhall+omega+2.6+estate+exhaust&_sacat=0

You can get both middle and back box, for roughly £100 on ebay and delivered by 11 December.

[Webby the Bear]

I believe the Eternal kits (see eBoy, I mean eBay) are recommended by the OOF faithful. I shall be purchasing cat back system once I save enough pennies.

One thing I’ve always wondered and keep forgetting to ask... is there a donut gasket or something like that between the cat and centre sections? Sadly when I last replaced the cat back that the college tutor agreed I could swipe off the omega they had (and pass my exhaust fitting section 🤣) I only had an tin of gun gum to use as ‘temporary’ gasket. And that was a few years ago 🤣

[YZ250]

And haven't asked but as I own a 2.6 Elite est any benefit in fitting a 3.2 exhaust? or is it the same?

No benefit other than it looks better with twin outlets. The exhaust is the same for both, just that the 3.2 has the twin exits on the back box. I had a 3.0 exhaust on my first Omega, which was a 2.5, many years ago. 

[YZ250]

I believe the Eternal kits (see eBoy, I mean eBay) are recommended by the OOF faithful. I shall be purchasing cat back system once I save enough pennies.

One thing I’ve always wondered and keep forgetting to ask... is there a donut gasket or something like that between the cat and centre sections? Sadly when I last replaced the cat back that the college tutor agreed I could swipe off the omega they had (and pass my exhaust fitting section 🤣) I only had an tin of gun gum to use as ‘temporary’ gasket. And that was a few years ago 🤣

When I fitted the Jetex to my 3.2, the original had a steel ring between the two flange parts. 

[gbh]

Well I only have a set of ramps so changing an exhaust would be a tall order and I don't have a garage. A patch I will check out tomorrow  as it's just before the joint on the back box almost touching in fact. Just wondered on brand and price with having 3.2 exhaust twin backbox instead of single/Is the slot out of bumper big enough? etc

[YZ250]

Just wondered on brand and price with having 3.2 exhaust twin backbox instead of single/Is the slot out of bumper big enough? etc

Same bumper. 
The water drips on that point and rots them out.

[Doctor Gollum]

You can change an Omega exhaust on the drive.

Easier to throw the local indy tyre place a few quid to fit it for you

[YZ250]

You can change an Omega exhaust on the drive.

Easier to throw the local indy tyre place a few quid to fit it for you

I drove mine up a pair of ramps and then jacked the rear up and put another pair of ramps under the rear. Confused the hell out of the neighbours. 
A pair of ramps at the front and axle stands at the rear would suffice. Only the flanges are bolted, the rest goes on hangers. Wiggling the back box duel pipes on was slightly challenging but other than that not too bad.

[gbh]

Well I suppose £160 for someone else to do it is pricey I suppose the cat end is the tricky part.Wish I had a pit at least but on your back under 1 set of ramps in December is indeed a challenge.Mind you garage said they would need it all day which seemed particularly extreme!!!!

[Enceladus]

There are no 'donut' gaskets between the front catalytic downpipes and the centre boxes. At least not if you are using factory fit or standard aftermarket equivalent parts. The flanges on each section should bolt tightly together and a smear of exhaust assembly paste on the pipe ends is all you should need.

The problem you are likely to encounter is that the flanges on the cat pipes have threaded holes for the bolts, two each side. The bolts will snap if you try and remove them so they'll have to be drilled out and replaced with a longer bolt and a suitable nut. That's the more difficult and time consuming part of the job. Unless the exhaust has been replaced previously and the cat side flanges are already drilled out.

Can still be done on the drive. Just need to make sure you have suitable drill bits to hand.

[kevinp58]

I got a jetex cat back system around 6 years ago and they are S/S and are guaranteed for life, I looked at mine yesterday as MOT is due and it looks as good as the day I put it on but iirc was £550 so not cheap.

[YZ250]

There are no 'donut' gaskets between the front catalytic downpipes and the centre boxes. At least not if you are using factory fit or standard aftermarket equivalent parts. The flanges on each section should bolt tightly together and a smear of exhaust assembly paste on the pipe ends is all you should need.

The link below shows the two metal rings at the bottom of the picture (metal gaskets). This is how mine is, and my previous Omega. 

https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjsk8GM2JrmAhXMzKQKHf0UDGEQjRx6BAgBEAQ&url=http%3A%2F%2Fwww.auspuffshop-geiz.de%2FAuspuffanlage-OPEL-OMEGA-B-3-2&psig=AOvVaw211s4K6lyWAowXLylxf4bc&ust=1575500784607705

[johnnydog]

I've got 2 x 3.2's and 1 x 2.6, and I'm sure they all have a 'gasket' between the down pipes and the centre pipes. The down pipes have a welded threaded oval shaped fixed clamp which is usually the issue when trying to remove the bolts as they can shear off in it. Next to this clamp is a tapered metal woven gasket that sits on the end of the pipe on which the flared end of the centre pipe mates to. This woven gasket looks like it is part of the downpipe as it is a tight fit. The two pipes are secured by the two bolts that pass through the loose oval shaped clamp bolting into the fixed clamp on the downpipes.
If you think the bolts are going to shear, you can cut a very thin slot across the clamp through to the bolt, which will release the tension on it and aid its removal. Alternatively some heat will help.
Bear in mind that if you get a 2.5 or 3.0 litre rear box (some suppliers will say that they are cheaper and will fit ok), but the exit pipes are shorter than the 2.6 and 3.2, and will result in exhaust deposits discolouring the bumper above the exhaust pipes, so I would suggest you try to get the correct ones for your car.

[biggriffin]

Hardest part with doing the exhaust on the drive is lifting it all up,  ensure you have some good drill bits for drilling out the flanges on the downpipes, as them bolts 99% of the time snap,  I use to drill them out with a 5/16 bit, and replace with M8 nuts bolts and washers.

[Nick W]

Well I only have a set of ramps so changing an exhaust would be a tall order and I don't have a garage. A patch I will check out tomorrow  as it's just before the joint on the back box almost touching in fact. Just wondered on brand and price with having 3.2 exhaust twin backbox instead of single/Is the slot out of bumper big enough? etc

45 minute job, on your own, in the street with just one pair of axle stands. Add another 15 minutes if you have to drill the system to cat mounting studs.

You refit it loosely from the front to the back, tightening in the same order when you're happy with the fit. The Eternal systems recommended here are well priced, good quality and value, and fit well.


The twin tailpipes are purely aesthetic if you like that sort of thing; they're no 'better' than a single pipe back box.


The earlier cars used a slimmer bumper so the tailpipes are slightly shorter than facelifts. Personally, I think the shorter pipe looks better on a FL, but I'd rather not see the exhaust at all.

[terry paget]

I find drilling out the old screws tricky, and prefer to release the existing screws with a blow torch. I much preferred the Senator arrangement, using nuts and bolts as original equipment. There I could easily snap the bolts, or grind their heads off.

[Enceladus]

There are no 'donut' gaskets between the front catalytic downpipes and the centre boxes. At least not if you are using factory fit or standard aftermarket equivalent parts. The flanges on each section should bolt tightly together and a smear of exhaust assembly paste on the pipe ends is all you should need.

The link below shows the two metal rings at the bottom of the picture (metal gaskets). This is how mine is, and my previous Omega. 

https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjsk8GM2JrmAhXMzKQKHf0UDGEQjRx6BAgBEAQ&url=http%3A%2F%2Fwww.auspuffshop-geiz.de%2FAuspuffanlage-OPEL-OMEGA-B-3-2&psig=AOvVaw211s4K6lyWAowXLylxf4bc&ust=1575500784607705

There are no donut gaskets shown on the Vauxhall /Opel EPC. That P.582 gasket seems to be to fit the Bosal exhaust you linked to. Nor is there any x-ref to a GM part number. So likely means the Bosal exhaust  boxes are not proper clones of the original parts.

If you look at the end of a correctly made centre pipe and the mating end of the cat pipes you can see why no gasket is required.

Nor is such a gasket shown in the Walker catalogue for a 2.6 (estate), since the OP mentioned Walker exhausts. Also of note is that Walker don't list anything for a 3.2.

When I last looked at one of these it did look as if there was something in between the flanges. Turned out to be the remains of some exhaust repair paste where somebody was trying to fix a hole in the end of the centre pipe.

[Webby the Bear]

I’ll just stick with the pot of jizz to seal it. That’s worked for over 6 years for me.

As for the threaded bits I’d drilled mine out many moons ago so just 2 x 13mm nuts and bolts each side now 👍

[Andy B]

....
 so just 2 x 13mm nuts and bolts each side now 👍

2 x M8  13mm is the spanner size 

[Enceladus]

I use M8 copper all metal self locking flange nuts (exhaust manifold nuts). These have the distorted thread arrangement used in the suspension and steering nuts etc., so not the nyloc type. Won't come loose.

[BazaJT]

As I understand it the cat back systems for all the V6s are the same other than the 3.0/3.2 had a twin outlet backbox a standard where the 2.5/2.6 had a single tailpipe*

* The saloon system differs from the estate system,so make sure you order one for the body style you have.

[gbh]

It's the original GM exhaust I presume with 60000 on the clock so it's had a good run.Cat to mid section joint looking quite rusty anything I can do to improve it? Also 1 cat has a whole threw the bottom protection plate about an inch diameter again anything I can do to preserve/repair it before further damage is done?

[Webby the Bear]

....
 so just 2 x 13mm nuts and bolts each side now 👍

2 x M8  13mm is the spanner size 

🤣🤣🤣🤣 sorry Andy 👍👍👍

[Andy B]

....
 so just 2 x 13mm nuts and bolts each side now 👍

2 x M8  13mm is the spanner size 

🤣🤣🤣🤣 sorry Andy 👍👍👍

 

[terry paget]

I’ll just stick with the pot of jizz to seal it. That’s worked for over 6 years for me.

As for the threaded bits I’d drilled mine out many moons ago so just 2 x 13mm nuts and bolts each side now 👍

I have always used Loctite SI 5990 high temperature copper silicone sealant, and never had a failure.

[Andy B]

I’ll just stick with the pot of jizz to seal it. That’s worked for over 6 years for me.

As for the threaded bits I’d drilled mine out many moons ago so just 2 x 13mm nuts and bolts each side now 👍

I have always used Loctite SI 5990 high temperature copper silicone sealant, and never had a failure.

Trouble being that the bolt usually shears because the bolt was fitted dry in the first place .... had they been wiped with something in the first place they're come out easier.

[terry paget]

I’ll just stick with the pot of jizz to seal it. That’s worked for over 6 years for me.

As for the threaded bits I’d drilled mine out many moons ago so just 2 x 13mm nuts and bolts each side now 👍

I have always used Loctite SI 5990 high temperature copper silicone sealant, and never had a failure.

Trouble being that the bolt usually shears because the bolt was fitted dry in the first place .... had they been wiped with something in the first place they're come out easier.

Torque setting is only 18Nm, but I agree if original assembly was dry rust can make them difficult to dismantle. I have found that heating to red heat usually releases them.

[Enceladus]

It's the original GM exhaust I presume with 60000 on the clock so it's had a good run.Cat to mid section joint looking quite rusty anything I can do to improve it? Also 1 cat has a whole threw the bottom protection plate about an inch diameter again anything I can do to preserve/repair it before further damage is done?

Would be useful if you could post up a picture of the hole. So we can understand exactly where you mean?

As to the rusty joints between the Cats and centre sections; the cats pipes are likely OK as factory Cats are stainless. Just clean any crud from the ends with a wire brush. The floating flanges might also need cleaning with a wire brush as they are mild steel and any broken bolts night need to be drilled out. The Cat side flanges have M8 tapped holes.

The ends of the centre sections might well be rusted through and beyond economic repair. The centre sections are likely also rusted through where the meet the rear silencer. Hence a complete Cat back system is the norm. The boxes themselves are pretty robust.

[kevinp58]

As I understand it the cat back systems for all the V6s are the same other than the 3.0/3.2 had a twin outlet backbox a standard where the 2.5/2.6 had a single tailpipe*

* The saloon system differs from the estate system,so make sure you order one for the body style you have.

I thought it was only the 3.2 that had twin exit pipes

[Doctor Gollum]

Nope, both

[Webby the Bear]

I personally think the single pipe looks a lot nicer 

[Migv6 le Frog Fan]

Your a weirdo.

[YZ250]

I personally think the single pipe looks a lot nicer 

But it lets everybody know that you've got a small one .......... engine that is. 

And having twin zorsts is wicked innit.    Having quad zorsts is even wickeder. 

[Webby the Bear]

But mine is small. Especially in this weather  🤣🤣🤣

[DrAndyB]

Yep, put a full ETS one (from the bay of Flea) on my MFL 2.5 and very happy.

Went for the 3.0 one as now got the twin pipes at the back 

My local garage where I get her MOT'ed offered to fit it for £20, so I snapped their arm off and said do the MOT was well !!!

Sounds the best it has been as the 1st replacement one I got was a vauxhall one and that seemed to even quieter than the original (and had car from new).

ETS one seems to have give her the V6 Growl back.