http://cgi.ebay.com/ebaymotors/ws/eB...195747756&rd=1
This is the item I was looking to buy,no cutting or welding involved .
Shipping is $110 to England,which isn't too bad.

 

Mine didn't have the bolt on flanges so i had to weld it. The one i bought was a magnaflow like the one below. Mine was only $60 shipped so if you look around and know what the inlet and outlet sizes you need you can save some money. There are different lenghts so besure to measure your old one.
http://cgi.ebay.com/ebaymotors/Magna...sid=p1638.m118

 

Just purchased that Magnaflow cat,I mentioned,price had dropped to $184.17 @ time of purchase,so a saving of $30 was had .
Not the cheapest option,I know,but at least I should be able to install it myself,should just be a bolt on affair.
Got to get this job done pretty quickly as the car is due for it's M.O.T test at the end of the month.Plus my road tax also runs out at the same time and I need a valid M.O.T certificate with at least 1 full month remaining to be able to tax it again.
It never rains,it pours .
Thanks for all your help guys,going to continue with this thread over in the "Exhaust System" section as this discussion no longer belongs in the "Fuel and ignition" section.

 

If you had a bolt on cat you should have just removed it and took a quick drive. You can still do this and even scare a few neighbors in the "mean time". I would do it because if it ran perfect disconnected, i would sleep a lot better. My moods are totally based on my car performance.

 

The old cat,which looks to be the factory original,is all one piece with the Y-pipe.To remove the old cat,I'd either have to cut just the cat off or unbolt the Y-pipe where it joins the bottom of the manifolds,plus then theres an oxygen sensor with nowhere to go.
Don't know why GM couldn't have just made the factory cat with a flange on so you could just unbolt it from the Y-pipe.Instead they made it all as one unit meaning you either have to cut and weld or buy one like the item I purchased.The new Magnaflow one is stainless and appears to come in two pieces according to the photo on the Jegs website : http://www.jegs.com/webapp/wcs/store...0002_393263_-1,although I purchased mine from E-bay for less .
Been miserable for weeks because of this car,but when it's fixed I'll be a happy bunny again .

 

I have removed 3 oxygen sensors and it was a total bitch each time. I ended up having to hit a wrench with a crowbar on one and the other two i had to stand on them while someone else held the manifold. I was almost convinced they weren't coming off but i never gave up. I wasn't reusing the old O2's so i soaked them in PB nut blaster for 3 days before. If these were on the car i would have had to come up with some kind of breaker bar on my wrench. You also need to get some special compound if you reuse em for them to work correctly. Good luck!

 

mrmint69,
Just ordered 1 new oxygen sensor for the driver's side.So I can just fit the new oxygen sensor into the driver's side of the new Magnaflow Y-pipe I have ordered,only thing I have to worry about now is removing those rusty old bolts holding the Y-pipe to the manifolds.
I'll soak EVERYTHING in WD 40 a few days before the install.
Thanks again for your help,you have been an absolute star these past few days .
Regards,Mark.

 

I just took a look at the one you showed from Jegs. If i remember when i was looking to buy one of these, the Y pipe and the cat were not connected. You might need some sort of clamp or welding for this connection. Knowing these kinds of direct connnects from my research you will probably end up modifying some of it like they say.

 

Hi all,
My Actron fuel pressure tester arrived today .Hooked it up,fuel pressure at idle was 38psi with vacuum line connected and 44psi at idle with the vacuum line removed.Out on the road it ran at 44psi at W.O.T and dropped to 38psi when I let my foot off the gas .Does this sound about right?
Best regards,Mark.

 

Sounds about right. How did it run at wot? At least the fuel problem is ruled out and you have a nice new tool.

 

Hi,
It was completely bogging down at WOT,running like absolute crap.Fuel pressure flicked from 38psi straight up to 44psi as soon as I floored it.
Just did a quick 1 mile test and both manifolds were glowing on return.
Managed to get it up to about 40mph .
Just waiting on the cat/y-pipe and the oxygen sensor to arrive,sure hope it fixes the problem.In the mean time I have a new MSD coil and a set of Delco plugs I could fit while I'm waiting.
Will keep you posted,best regards,Mark.

 

Hi all,
Have the cat/y-pipe, oxygen sensor and some new copper gaskets now,that's the good news.
I soaked the collector/manifold studs and nuts in WD-40,let it sink in for a few hours.While I was waiting I went and purchased the correct size deep socket for the nuts on the six studs that hold it all together.
Had the car up on some ramps,access was fairly straightforward,laying on my back.So I make a start on the first one using my 3/8" ratchet drive and an extension.It was pretty damn tight as I imagined it would be,so I applied a bit more force and it started to creak and I thought it was going to undo.The stud then sheared clean off and I managed to mangle my little finger on my left hand in the process .
I made an attempt on another one but that one didn't want to budge either and I didn't fancy shearing another stud,so left it alone.
I'm not entirely sure if the nuts should just undo and thread back down the stud or if the whole nut/stud will just unscrew from the manifold flange threads.
If I take it to a garage I don't see how they will fair any better than I did,after all it will only be a guy with similar tools to me,only difference being he will have the use of a lift.If they are all just going to shear off I might as well do it myself and save some $$$.
Not sure how difficult it would be to use a stud extraction kit in that area,not that I have one anyway.Why didn't GM just use a simple nut and bolt instead of a stud?
Am just about ready to cover this car with fuel and toss a lit match into the equation .
Any suggestions or sympathy would be most welcome.
Apologies for the long post, Moderators feel free to move the entire thread to the exhaust section as it would probably be better suited there.
All the best,Mark.

 

I let mine soak for days and they came out without breaking. There is not a big rust problem here so that probably helped. I put headers on so it wasn't a problem if one broke. If you would have know this would have happened you could have just gone ahead and welded a new cat in place and not messed with the bolts. If you stop now and go another route thats one choice and the other is to try and remove the rest and see what happens. You could also remove the manifolds from the heads and pull them out and get the broken part out. With your luck you would probably break one off in the head and be more screwed. Well the only thing i can say is it never fails that you wanted to just unbolt it and bolt it back up and be done and now your not really even started and have tough decisions to make. I feel your pain and wish you Good Luck!

 

Thanks for your kind words mrmint69 .
I did a search late last night and it seems that a number of people have encountered the exact same problem when trying to remove the y-pipe studs.
I'm going to go ahead and attempt to remove the other five,but will soak them further beforehand.The weather here is pretty awful at the moment,cold,high winds,rain etc,and I have to work outside due to not having a garage.Damn English weather,thats what caused all the corrosion in the first place .
On my previous attempt the exhaust system was stone cold,maybe it would be easier if I got some heat into it first,buy letting it run a while .
I have Friday and Saturday off work,so if the weather is ok then I'll have another go at it then.
On a more positive note I am very happy with the quality of the new Magnaflow part,just a shame UK customs got their hands on it and charged me the equivalent of $66 for the privelige .
Will let you know how things go,all the best,Mark.

 

My exhaust gets hot within seconds and if it is running a while it takes forever to cool down. Since you have a clogged cat you will heat them up even faster for be careful not to burn yourself. When i had a n exhaust leak i remember have 30 seconds or so before they were to hot to handle. Let them soak and then tap on the ends to help break the bond. I tried turning mine just a bit and resoaked them. I sprayed mine over a 3 day period.