Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Webby the Bear on 12 January 2014, 11:40:17

Title: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 11:40:17
Hi guys, how are ya? :)

Ok, got pay day coming up in a couple of weeks and I'm fed up with using repair paste on my exhaust  ::) so I'm going to replace.

Looking at my exhaust it's all in a shoddy state :( so after speaking to Martin yesterday we discussed just replacing the whole thing from Cat backwards. I'm not opposed to that due to the state of it.

Forgive the really stupid question but if I buy a ''cat back'' will I be getting everything from the green arrows back to the back-box? I presume so but worth asking for clarity :)
(http://i1226.photobucket.com/albums/ee402/webbybear1/exhaust_zps679df3fb.png) (http://s1226.photobucket.com/user/webbybear1/media/exhaust_zps679df3fb.png.html)

I've done a search on here and the only advice on what parts to buy is to go stainless steel. That's fine but being a student I'm pretty broke at the moment so looking for a bi of a compromise in this area. Can anyone recommend a decent budget exhaust system?

Also I've noticed a bloody great hole next to where the O2 sensor lives on the downpipe.... can the downpipe be purchased separately?

Re fitting I'm thinking that as I'm replacing everything cat backwards then I simply undo the exhaust from the cats and remove off the hangers, then drag it out as all one piece?

And on refitting get it on the hangers then do it up to the cats?

Any advice you can give me would be brill! :)

Title: Re: Exhaust from Cat backwards purchase advice
Post by: YZ250 on 12 January 2014, 11:49:06
Yes, cat back system is from the "two bolt flange" backwards, so your assumption is correct. It's worth soaking those bolts in plus gas a few days earlier as the thread is in one half of the coupling flange. If they shear off, you will have to drill them out and use nut and bolt method.  :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 11:51:37
Thanks mate :)

Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 11:56:18
just had a thought.... does the down pipe include the cat? Or is the cat separate?
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 12:00:58
PPS, found this....

http://www.ebay.co.uk/itm/Opel-Vauxhall-Omega-B-2-5-2-6-V6-Estate-Silencer-Exhaust-System-352-/261111236317

Rubbish or any good? Or would I have to suck it and see? :)
Title: Re: Exhaust from Cat backwards purchase advice
Post by: YZ250 on 12 January 2014, 12:02:26
Forgot to say, cosmetically speaking it's worth putting a 3.0 system on it as it will hang in all the same places.  :y

Title: Re: Exhaust from Cat backwards purchase advice
Post by: hotel21 on 12 January 2014, 13:26:10
I bought the one in your eBay link for my 3.2 estate around septembertime. Only needed the two centre sections as car has an irmsher back box but worth buying whole thing. Well enough made, fitted where it should, and mated to irmy box no problem.

But had to drill 3 of the 4 bolts out. The other one was drilled out by me a few years ago when I replaced exhaust time before.

System noise is acceptable and no knocks or rattles. Sits high under the car which is good as car is also lowered somewhat!

And I haggled a bit with the seller by submitting a best price offer. Wasn't much but even a tenner is a tenner to a student!   :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 13:39:51
I bought the one in your eBay link for my 3.2 estate around septembertime. Only needed the two centre sections as car has an irmsher back box but worth buying whole thing. Well enough made, fitted where it should, and mated to irmy box no problem.

But had to drill 3 of the 4 bolts out. The other one was drilled out by me a few years ago when I replaced exhaust time before.

System noise is acceptable and no knocks or rattles. Sits high under the car which is good as car is also lowered somewhat!

And I haggled a bit with the seller by submitting a best price offer. Wasn't much but even a tenner is a tenner to a student!   :y

Awesome, cheers H21!  :y

Re the bolts.... is that cos they were rusted in place? Do I need any replacement bolts and gaskets?  :) Re bolts if they come out I was simply going to clean the threads up and put a bit of oil on the threads and re-use them.
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Nick W on 12 January 2014, 13:41:02
I've an almost new, complete cat back system from a 3.0l saloon. It was part of the job lot of bits that came with my project engine, and is of no use for my estate.

Webby, it's yours if you care to collect it.

Nick
Title: Re: Exhaust from Cat backwards purchase advice
Post by: 05omegav6 on 12 January 2014, 13:50:51
Can't say fairer than that :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 14:21:01
PM sent Nick, thanks very very much!!!!
Title: Re: Exhaust from Cat backwards purchase advice
Post by: martin42 on 12 January 2014, 15:25:29
Bolts on passenger side are ok as we had them off to refit downpipe when doing heads,when you get exhaust pop over to mine and fit it here :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Keith ABS on 12 January 2014, 15:40:23
  With referance to using stainless steel system, was there a system in the ads just this week?
keith B
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 15:50:55
Bolts on passenger side are ok as we had them off to refit downpipe when doing heads,when you get exhaust pop over to mine and fit it here :y

You sure that's ok, Martin? Thanks mate very kind!!!  :) :) :) :)

I couldn't remember if we'd took them off but now I recall we had to get them off to manouvere the downpipe in to place :)
Title: Re: Exhaust from Cat backwards purchase advice
Post by: chrisgixer on 12 January 2014, 16:02:27
http://www.omegaowners.com/forum/index.php?topic=120472.msg1534263;boardseen#new

:-\
Title: Re: Exhaust from Cat backwards purchase advice
Post by: YZ250 on 12 January 2014, 16:30:29
Forgot to say, cosmetically speaking it's worth putting a 3.0 system on it as it will hang in all the same places.  :y

I've an almost new, complete cat back system from a 3.0l saloon. It was part of the job lot of bits that came with my project engine, and is of no use for my estate.

Webby, it's yours if you care to collect it.

Nick

Result. Nice one.  :y

Reference the flange bolts, they rust in but if you can get some movement from them, regardless of how little, you can gradually get them out by undoing until they resist, do them up slightly, undo a bit more and so on until the resistance is less. If you can get them out, they are re-usable.  :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Nick W on 12 January 2014, 16:47:11


Reference the flange bolts, they rust in but if you can get some movement from them, regardless of how little, you can gradually get them out by undoing until they resist, do them up slightly, undo a bit more and so on until the resistance is less. If you can get them out, they are re-usable.  :y

Getting them out is the key; even if the female threads are knackered, it's easy to run an 8.5mm drill bit through them, and swap to longer bolts. That's what is now on mine.
Title: Re: Exhaust from Cat backwards purchase advice
Post by: martin42 on 12 January 2014, 16:57:44
He learnt that trick yesterday  :D
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 12 January 2014, 19:50:55
Very true! It's amazing the tips you pick up from watching and listening to experts!

I have a tap n die set so drilling and making new holes wouldn't be a problem  :)
Title: Re: Exhaust from Cat backwards purchase advice
Post by: hotel21 on 12 January 2014, 22:11:30
In my opinion, not worth the hassle of retapping the holes. Simply drill through and use bolts instead of studs and nuts. That way when they seize/rust and you need to seperate then a hacksaw or cut off tool through the bolts then drift them out and job done.  :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Andy B on 12 January 2014, 22:43:46
In my opinion, not worth the hassle of retapping the holes. Simply drill through and use bolts instead of studs and nuts. That way when they seize/rust and you need to seperate then a hacksaw or cut off tool through the bolts then drift them out and job done.  :y

Or. ....... drill & tap the original holes & use stainless bolts from work  ::) ::) ::)

I wonder what prat at Vauxhall decided to tap the part of the exhaust that you're like to keep rather than the bit that rusts and you throw away  ::)
Title: Re: Exhaust from Cat backwards purchase advice
Post by: kevinp58 on 12 January 2014, 23:09:29
In my opinion, not worth the hassle of retapping the holes. Simply drill through and use bolts instead of studs and nuts. That way when they seize/rust and you need to seperate then a hacksaw or cut off tool through the bolts then drift them out and job done.  :y

Or. ....... drill & tap the original holes & use stainless bolts from work  ::) ::) ::)

I wonder what prat at Vauxhall decided to tap the part of the exhaust that you're like to keep rather than the bit that rusts and you throw away  ::)









Or just use Stainless nuts and bolts.  :y :y ::)
Title: Re: Exhaust from Cat backwards purchase advice
Post by: M Kerr on 13 January 2014, 01:00:54
 :o  What a result this thread is!  I'll sleep well knowing that Utopia simply exists! Well done all!  :y
Title: Re: Exhaust from Cat backwards purchase advice
Post by: Webby the Bear on 13 January 2014, 09:26:32
Yeah again a massive thanks to Nick (who i'll hopefully see Sunday) and massive thanks to Martin for previous help and help with fitting.

love OOF!!!!

ps, re the downpipe..... do you have to buy the cat with the down pipe as its all one pipe so to speak? noticed a big hol next to my o2 sensor :(
Title: Re: Exhaust from Cat backwards purchase advice
Post by: kevinp58 on 13 January 2014, 16:25:05
Yeah again a massive thanks to Nick (who i'll hopefully see Sunday) and massive thanks to Martin for previous help and help with fitting.

love OOF!!!!

ps, re the downpipe..... do you have to buy the cat with the down pipe as its all one pipe so to speak? noticed a big hol next to my o2 sensor :(








Yes I think they are all integral for the V6's  :y