Catalytic converter shield

[ABV-VR6 12]

Today I was cleaning up my catalytic converter... I want to keep my oem one for many reasons, it's well made and not that restrictive, not rusted out either plus I have the very rare Japan market only cat with the probe in it that wires to my cat light in the cluster. Anyways long story short, the heat shield is held by 6 bolts with 4 of them going to a clip holding a little square that slides in the clip and also is threaded to receive the bolt. Two of them are cracked in a half, 1 bolt was missing brief the perfect scenario for a rattling shield... Went on 7ZAP to find out the diagram do not provide any part number for this... I'm sure I'm not the only one who had issue with this, does anyone know the part number for those and the type of bolts used? Cheers 

[1xshaunx1 27]

I don’t know the proper part number I’m afraid but couldn’t you use a speed nut or captive nut like below. 
https://www.eurocarparts.com/search/300330970?type=shopping&msclkid=d7e8d2334ec315c86d72b013b925bfc7&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping - Brands&utm_term=4579809529099503&utm_content=Shopping - Miscellaneous Engine Parts-1 - OE-Quality

 

 

https://www.bing.com/search?q=captive+nut&form=APIPH1&PC=APPL

[ABV-VR6 12]

11 minutes ago, 1xshaunx1 said:

I don’t know the proper part number I’m afraid but couldn’t you use a speed nut or captive nut like below. 
https://www.eurocarparts.com/search/300330970?type=shopping&msclkid=d7e8d2334ec315c86d72b013b925bfc7&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping - Brands&utm_term=4579809529099503&utm_content=Shopping - Miscellaneous Engine Parts-1 - OE-Quality

 

 

https://www.bing.com/search?q=captive+nut&form=APIPH1&PC=APPL

Captive nut, that's the proper word! The joy of being French speaking 🙄🤣😁. Thanks so much, that part you linked is exactly what I need. Just have to do a search on ebay with the proper wording and find the equivalent. Cheers! 

[ABV-VR6 12]

Alright, I'm just going to round this up in case someone in the future has a rattling shield. So yesterday I was at the dealer, VW doesn't have the fasteners for it as it was a package deal from the manufacturer "Eberspacher" who manufactured the cat converter for them. So the only way to fix this is like Shaun said above and finding a captive nut clip. I'm trying to see if I can find them in stainless steel. Bolt size is M6x1.0 by the way. 

On a side note, I can't believe how strong and good quality the OEM cat is. Good old German stuff! 26 years old and cleaned up really nice, no rust, impressive! 

[Keyo 47]

Yes the factory long life is the best quality money can buy- the oe manufacturer was Leistritz which was later purchased by Eberspacher. Ive been collecting this  16v exhaust for the last few years - some odd nos parts do come up in the States.  

This is for sale- shows how well its has lasted. 

https://www.ebay-kleinanzeigen.de/s-anzeige/vw-corrado-vr6-original-abgasanlage-leistritz/1983881640-223-1100

v 

 

Edited March 5, 2022 by Keyo

[ABV-VR6 12]

Yes, Leistritz was my exhaust line. It only had fine rust on the surface, amazing exhaust system. I had to drop the rear frame to get it out, the middle suit case plus the muffler were in one piece. I sold it but kept the cat. I ordered a 2-1/2" line from techtonics so the engine breathe better. Anyways I'm blown away by the state it is after all those years, it's nuts! Cheers 

[fla 9]

15 hours ago, ABV-VR6 said:

Alright, I'm just going to round this up in case someone in the future has a rattling shield. So yesterday I was at the dealer, VW doesn't have the fasteners for it as it was a package deal from the manufacturer "Eberspacher" who manufactured the cat converter for them. So the only way to fix this is like Shaun said above and finding a captive nut clip. I'm trying to see if I can find them in stainless steel. Bolt size is M6x1.0 by the way. 

On a side note, I can't believe how strong and good quality the OEM cat is. Good old German stuff! 26 years old and cleaned up really nice, no rust, impressive! 

Thats pretty impressive JF!  How did you manage to get it so clean and shiny?

Hasan

[ABV-VR6 12]

Thanks Hasan. It's was dark brown prior, spent about 4 hours on it. I never thought it would clean this shinny, it's like a mirror. It's mostly due because it is a high quality stainless steel, magnets don't react at all with it. 

First I wrapped it with an old towel poured a rust remover product on it and wrapped it up with a garbage bag after to keep it moist over night. I then used 3M scotch bright white pads "light duty" and hand scrubbed it for about 3 hours. Made little squares and dipped in the same solution. At this point all was back to stainless color. Then I finished it off with an extra fine brass wire wheel on a drill and ended up with mirror finish. 

I've seen tons of videos where people sink their cat in dish soap or a degreaser solution to remove the carbon inside. I'm tempted to try it but it looks really clean already. I look with a flash light and I can see through easily... 

https://www.amazon.ca/POR-15-40704-Rust-Remover-quarts/dp/B07NRDPRR3/ref=asc_df_B07NRDPRR3/?tag=googlemobshop-20&linkCode=df0&hvadid=341829452089&hvpos=&hvnetw=g&hvrand=12858863786455546881&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1001953&hvtargid=pla-817978672955&psc=1

 

[fla 9]

Mine is that browny colour but might have a go, although its  still on the car so might be a bit harder..

[ABV-VR6 12]

7 hours ago, fla said:

Mine is that browny colour but might have a go, although its  still on the car so might be a bit harder..

Wish I had taken a picture prior... But it was all brown! Definitely easier to remove it if you want to do this. Rest of the line is new so the cat was definitely standing out, I had to do it! Cheers 

[Cressa 43]

Just had a read, quality work and a lot of effort 👍

[ABV-VR6 12]

9 hours ago, Cressa said:

Just had a read, quality work and a lot of effort 👍

Thanks much appreciated! Cheers 

[oneohtwo 8]

Was it difficult to get off?

I've got a hunch my cat is a bit coked up from when the engine was old and worn. The hunch is that the plastic trim around the gear shift can get warm, especially in slow moving traffic, and coincident with everything getting warm, there's a weird smell. It's only really where the gear shift is, which is just where the cat is. Heat sheild is all intact as well. I've read both heat and smell could be signs of a blocked cat, and there used to be loads of carbon deposits in the exhaust before the engine rebuild so it stands to reason, but I can't verify it. 

I have contemplated getting it replaced just to see if it makes a difference, but seeing yours, and testimony from Keyo about how good the Leistritz parts are, I am reluctant to junk it if it is in perfectly good order.  I'd rather keep it, especially if it can be cleaned, than replace it on the off chance for an inferior product. Car is parked on road, so doing any work to it isn't easy at the moment.

Edited March 17, 2022 by oneohtwo

[ABV-VR6 12]

Yes, I would say that smell and heat is created by a partially plugged cat. On my Japanese Corrado, there's a sensor at the rear of the cat reading the temperature difference, when it gets plugged like that, a red light comes on the cluster marked "CAT". 

It's not that difficult to remove, there's 3 bolts that most likely will break off,  better to replace them anyways while doing this. And on the other side it was a collar. It's simple to do but if the car is in the street it may complicate things for sure. 

What I have done is mostly esthetic although that grime on the outside once warmed up must smells. I have watched a few videos where people soak overnight their cat in dish soap or paint thinner to clean the inside and restore performance. I'll say the consensus is a mixed review... On the plus side it cost almost nothing to do so there's not much to loose trying I'll say. Cheers! 

[Dox 22]

A cat needs to be hot to work (later cars have secondary air pumps to push oxygenated air into the cat to help warm it up and work quicker) as do lambdas (hence they have heaters built in).

Is the second after cat sensor another lambda? Again later cars have pre and post cat lambdas to measure the effectiveness of the cat.

Edited March 18, 2022 by Dox

[ABV-VR6 12]

You are right, it does need to be hot to work. That said within certain specs. To know if your cat is plugged, you use a temperature laser before and after the cat and if there's a big difference in temperature then you know the cat doesn't breathe and is plugged.

But my car came factory without secondary air pump and EGR. Never seen that in a later spec Corrado. There's no opening in the intake or hose to connect anything. And it's not a second lambda sensor, I only have one at the front. It's a sensor that only detects high or too high temperatures indicating the cat needs replacing. There's a cat red light in the cluster that will come on if it does. Only Japan got this. I have a friend with a Japanese G60, same as me. It's 100% factory and if you look at my cat part number, it finishes by H and I can't find that version anywhere! I can take a closer picture of the sensor if you're curious? Cheers 

[Dox 22]

I wasn’t suggesting your car had SAI, cars in general post Corrado have it to warm the cat.

 

Id have thought if the cat was blocked down stream would be cold? I’ve seem videos of cars with blocked / broken up cats with there manifolds and downpipes glowing red, so a post cat temp sensor seems odd

[Dox 22]

 

[ABV-VR6 12]

Secondary air pump and EGR are on all North American late spec Corrados. That's why I'm surprised by mine not having it! Do you in the UK? 

I was wrong, it is like you said, hotter inlet, colder outlet. 

[Dox 22]

5 hours ago, ABV-VR6 said:

Secondary air pump and EGR are on all North American late spec Corrados. That's why I'm surprised by mine not having it! Do you in the UK? 

I was wrong, it is like you said, hotter inlet, colder outlet. 

Cat with one lambda, no other emissions stuff in official U.K. imported cars.

[Dox 22]

An over heating cat can also be caused by oxygen / fuel burning inside a hot cat

[oneohtwo 8]

I think what I'll have to do is take it in to an exhaust fitter and get them to take the CAT off and have a look. I was taking it anyway to get a new exhaust as the current stainless one is too droney, most likely to Longlife. If they get it off and find it's duff then I'll have to replace it there and then, but if not they can refit it. Maybe I can then take the OE one back with me and try cleaning it, so at least I'll still have the original part.

[ABV-VR6 12]

I think that's a very good way to see this, good decision. I'm pretty sure I've seen in the past NOS cat on ebay from that seller in Latvia but it was pricey! 

I went with a standard exhaust system over stainless as well, heard you get drone with stainless steel. I know it won't last as long but it was also 1/2 the cost. Plus I won't drive the car in the rain anyway... 

Keep us posted! 

[seanl82 23]

41 minutes ago, ABV-VR6 said:

I think that's a very good way to see this, good decision. I'm pretty sure I've seen in the past NOS cat on ebay from that seller in Latvia but it was pricey! 

I went with a standard exhaust system over stainless as well, heard you get drone with stainless steel. I know it won't last as long but it was also 1/2 the cost. Plus I won't drive the car in the rain anyway... 

Keep us posted! 

Some drone but most are ok, especially with a resonated system (front silencer). Where did you get a stock exhaust system from? They've been obsolete for a long time over here so stainless is the only real option as I'm not sure if anyone makes custom mild steel systems. There are no real aftermarket alternatives either.

[ABV-VR6 12]

Mines not OEM anymore either. There's a company that is the bench mark in aftermarket exhaust system here (techtonics) and they offer stainless or aluminized (I think) versions. I went for the non stainless, 2 res, oem cat, Borla stainless muffler.