Replacing front pipe and cat

[tom50]

As the flanges have corroded front pipe to cat , on both cat and front pipe, I'm going to have to replace with new exhaust parts which i have purchased cat was no longer available from Klarius, The problem is the removal of the 4 bolts that hold the front pipe to the front pipe My mechanic mate Isn't optimistic on the bolts coming out even with heat and then the time-consuming drilling out of the bolts Isn't something he wants to do as it would take hours, However i have found a 2nd hand Exhaust manifold off a Vauxhall Omega 00-03 2.0 Petrol X20XEV Exhaust Manifold 90411885 198367 My manifold bears the same part number 90411885 And this site suggests it also fits the Cavalier 1995 ,with ECOTEC X20XEV Engine,

http://oemcats.com/oem-parts/90411885.html

Whilst looking at the manifold on my engine, does the metal pipe held in place by the heat shield on the top of the manifold, that runs under the heat sheild on the right hand side which also that connects to a rubber hose that runs to the left i think feeds into a valve(not EGR) as that is connected to the engine, and then to the secondary air pump connect screw into the manifold ? As from the photos supplied of the item , i dont see any hole for it to connect too,

The Exhaust manifold should be removable without drama as it was removed a few years ago when the head gasket was replaced

[Robsey]

An X20XEV is an X20XEV, no matter which car it comes from. Vectra-B, Omega-B, Cavalier mk3 and Calibra.

The manifold, and front pipe should be the same, but differences will be evident with middle pipe and back box.

Be careful what you buy regarding catalytic converters.
95% are garbage, and will fail the emissions test within 12 months of installation.

You need to get an "approved" cat.
Officially you do not have to... but I cannot think of any non-approved cats that have passed more than only the initial / first mot test.

As for the pipe across the front - is that not for the thermostat or something?

As for the XEV unit, this has been a nightmare unit to work with. Over the years they changed the ECU wiring, added different sensors and senders.

I would not be surprised if the Omega manifold has additional parts, but...
The Cavalier should not have parts that a later vehicle such as a Vectra-B or Omega-B does not have.

[tom50]

Thanks for the quick reply, I'm not overly fussed about MOT emissions I can get around that, least of my worries tbh , this pic though from the opel couterpart shows what i refere to https://external-content.duckduckgo.com ... ipo=images or this
See the metal pipe to the lkeft of the V bracket on the heat shield does this screw into the mainfold, as this is another or could be head achce loads of ££££ In labour time

https://i.ebayimg.com/00/s/NTQwWDcyMA== ... Y/$_86.JPG

[ilovedmymantas]

- From an earlier post of mine, with the heatshield off:


The trombone slide as i like to call it, is attached to the manifold by two torx bolts so if the manifold absolutely has to be replaced(which I doubt) it shouldn't cost any more.

I must admit I have no idea how this part works. When you see the item in situ you think some exhaust gas is coming out of the manifold into the metal pipe - it isn't! The two parts from the pipe are capped, more like locating lugs.

Despite the correct part number ( 90411885 ) the catalogue illustrations don't help because they're lacking detail. There should be two drilled 'dimples' next to where it bolts on. If you look closely at the gasket there's no corresponding holes, they're blank.


Your mechanic sounds like me, pessimistic and always looking at the worst case scenario! Despite that things do sometimes work out, four bolts shouldn't be much of a challenge.

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As Robsey suggests, get an approved cat, anything else is a false economy.

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My car looks more like the ebay link you posted.
I notice on the right hand side the hose from the sump in both cases is angled. This should be a factory modified part shown in my pic- the rectangular box.

[tom50]

I see two more bolts to snap, that hold it in, If i have to go down the route of replacing the manifold , And on the picture of a new non Vauxhall new manifold the gasket that it ships with has the holes blanked off which makes you wonder does it do anything useful? if no exhaust gasses are being recirculated via this pipe, When I got the car that rubber pipe that connected to the metal pipe work was perished so was doing nothing thinking about it, And the layout on mine is the same as the pictures i posted the pictures of a new non Vaux part presumably OE standard shows it blanked on the gasket too, And you can see the inside of the manifold , the pipes for recirculation don't look like they do anything https://www.ebay.co.uk/itm/374728572247 ... media=COPY

[Robsey]

Image 1 shows the holes blanked - image 3 shows them drilled or punched out.

Maybe that is an option dependent upon territory.

Looking at TIS, It is connected into the manifold where it bolts onto it.





It is called the Secondary Air Injection unit.

[tom50]

Thanks for finding out what it is called, and as its name suggests it connects to the secondary air pump after some diaphragm type thing that has vacuum pipes and sensors on it I now have a 2nd hand Exhaust manifold The 4 flange boltholes are serviceable threads intact but will need the threads cleaning chasing out i have had a bolt through them all, but a bit tighter than it should be I should be able to wind them in without any tools ,

Looking at the manifold where this secondary air injection connects to the manifold, there is no way for exhaust gases to get into the hollowed out chambers because the gasket will seal them off and there are no holes in the chambers other than the holes the pipes fix too, the only exhaust gas routes out of the manifold are the 4 exhaust gas ports

So it would appear to do nothing Just like the secondary air pump which no longer works on my car Motor i think died last year and the price of a new one, no, thanks So if no exhaust gases are able to escape into that injection system It maybe surplus to requirements , it will save tapping all the boltholes out and finding new bolts because it's unlikely the original bolts will come out of the manifold on the car for its heat shield and injection System


Hopefully you can see what i mean from this image of the inside view of the manifold https://i.ebayimg.com/images/g/AUwAAOS ... -l1600.jpg

[Robsey]

Although you say in your own circumstances, that you are not too fussed about the emissions, as you are able to work around that....

I wonder how much effect the secondary air injection unit actuially has on the emissions.

It would be a bit of a nonsense if it's benefits are minimal.

[tom50]

Well my limited understanding of how the secondary air pump and system is it only works during a cold start runs for around 2 mins then stops (pump) and if the chambers in the manifold are blanked off, (no exhaust gases are emitted what is warm air? But it would create a vacuum as it would also be airtight once secured to the cylinder head (even if the gasket didn't blank off the holes into the manifold, so why have a one way valve, makes no logical sense to have it The secondary air pump is supposed to below warm air or fresh air into the exhaust side of things but only whilst engine cold they don't continually run, mine didn't, So how can it be lowering emissions if it ain't blowing air into the system ? And if that cannot get beyond that gasket or the hollowed out space in the manifolds casting ,plus it's always passed the emissions test My mate was surprised as i was

[vexorg]

There is EGR and SAI. The SAI only blows air into the manifold when cold (choke on in old fashioned terms) and burn off any remaining rich fuel mixture to heat the cat quicker.

[tom50]

The SAI is defunct if the exhaust gasket is blanking it off, Plus there is no pathway into the exhaust output from the manifold just a blank chamber, So unless the gasket isn't acting as a blanker, and there is no extra holes or ports on the head the SAI does nothing, It maybe why the SAI pump fails Because it's pumping air, and it can't go anywhere But if there is no escape or leak of exhaust gases from the manifold with the SAI pipes and non-return valve removed that's the way it can stay for me as the PUMP No longer Works