It REALLY IS a miracle! (Pre cat related)

Anonymous · March 25, 2006, 12:36

So I got my old manifold taken off yesterday and the new Che one fitted. The pre cats were absolutely mint.. no scratches, cracks, degredation nothing... perfect criss-cross honeycomb throughout. Pleasing I thought... still glad they are out of the car now, but it just goes to show, even at 65k miles on the clock, you might be ok... it's never too late!

Anonymous · March 25, 2006, 13:29

That's good but now's the time to gut them ASAP before your next mod is a new engine.

Anonymous · March 25, 2006, 13:39

Nah I think I'm going to leave them for a few more months and just keep an eye on them from time to time.

Anonymous · March 25, 2006, 13:42

How easy did you get your old bolts off and the 02 sensors out mate?

Anonymous · March 25, 2006, 14:48

Bolts were pretty straight forward thankfully... just used lots of plusgas on them before I started then they came off with a bit of persuasion and a decent ratchet. The O2 sensors were just as forgiving, although I can imagine it being nigh on impossible without an O2 socket (22mm)

Anonymous · March 25, 2006, 14:57

Just managed to check mine for the first time and they seem OK as well (no symptoms of failure, just checking to ease my mind). My O2 sensors were ba?@*ds though. Soaked in penetrating spray for a good week and still were tough.

Still, will worth losing skin of both hands and one of me forearms for peace of mind. s:)

s:)

I think I'll still gut them though!

Anonymous · March 25, 2006, 15:19

Quote from: "Slurpy J"Nah I think I'm going to leave them for a few more months and just keep an eye on them from time to time.

s:? :? s:? Why?

Anonymous · March 25, 2006, 15:26

Hmmmm

see this

Thats the bottom of the precat on my 2000 MR2, the tops looked perfect. Don't want to panic you or anything but I would still get them out.

Anonymous · March 25, 2006, 16:05

You can see they're okay, which means your engine is fine and dandy. Knowing that, wouldn't you rather get rid of them now before they all collapse next week and take your 1ZZ with them?

Anonymous · March 25, 2006, 17:43

Hmm 'spose you're right.. I'm just a bit worried I guess that if I start messing around and get it wrong I'll be in a bad state, or that I'll end up shearing bolts etc.

How many more bolts do I have to get out after the O2 sensors and the manifold shield is off?

I also cant jack the rear of my car up as the axle stands we have wont fit under my 2... s:(

s:(

Anonymous · March 25, 2006, 18:22

About 5-6, IIRC. See GSB's thread at the top and count 'em.

So what if you shear a bolt? Much better than an engine going pop... s:wink: :wink: s:wink:

markiii · March 25, 2006, 20:30

if your worrying about bolts, I take it from that you haven't already uunbolted teh cat from teh manifold? in which case all you've proved is that the top is intact.

the bottoms could still be a mess

Anonymous · March 26, 2006, 02:57

SlurpyJ: Good news indeed. You still have a chance.

There are two typical failures you're looking at: precats go from above, they go from below.

You've verified they are good from above. That's great. No cylinder scoring. If they've gone from below, the motor is dead. Sounds like your car is running good, so we'll assume the bottoms are good - you won't know until you decat.

Two things to keep in mind: 1) If the precats go, they can go between oil changes and you'll never get a warning sign. 2) Your mileage is way past the average failure point. You're overdue for the nightmare.

It's totally your decision. Leave them in and attend church regularly, praying and wishing and hoping and yearning that you'll be one of the lucky ones, or trust nothing and rip them out.

Time, unfortunately, is a luxury you do not possess.

red_leicester · March 26, 2006, 09:25

Quote from: "southerneditor"2) Your mileage is way past the average failure point. You're overdue for the nightmare.

Slurpy's mileage is way past the average failure point of those that have failed. Not of every Roadster in the world.

Anonymous · March 26, 2006, 16:03

Well, I've decided to just take out the manifold completely and replace it with one of Che's ones. I've ordered it off him today (with a short shift kit) and will get it fitted next week at the garage...

At least then I'll never have to worry about those sodding cats again! (whether they're fine or not...)

Anonymous · March 26, 2006, 18:19

good choice mate. Only thing to be sure of is when you remove your old manifold, make sure the bottom of the precats is intact otherwise the bits of it will be inside your cat and will probably still find their way into your engine.

Richie

Anonymous · March 26, 2006, 18:24

...so, say they are broken and they are inside my main cat, what can be done about it?

kanujunkie · March 26, 2006, 18:51

Quote from: "Slurpy J"...so, say they are broken and they are inside my main cat, what can be done about it?

nothing, rip em out, throw em away and replace it, its scrap

Anonymous · March 26, 2006, 19:30

Quote from: "Slurpy J"...so, say they are broken and they are inside my main cat, what can be done about it?

you would have to replace your main cat I believe.
you may be able to shake some bits out of the main cat etc however i wouldn't find this reassuring that all bits of precat floating about were removed.

Cheers,

Richie

Anonymous · March 27, 2006, 09:00

Hmm, well I'm still not convinced there will be anything wrong with mine, but may as well replace the manifold once and for all and be sure. I'll ask the garage to save the old manifold for me so I can firstly check how bad the degradation was and secondly gut it and send it out to anyone who wants a gutted manifold.

kanujunkie · March 27, 2006, 09:25

The club also has a manifold for use if anyone wants to use it

Anonymous · March 27, 2006, 15:48

Quote from: "Slurpy J"Hmm, well I'm still not convinced there will be anything wrong with mine, but may as well replace the manifold once and for all and be sure. I'll ask the garage to save the old manifold for me so I can firstly check how bad the degradation was and secondly gut it and send it out to anyone who wants a gutted manifold.

I'm sure it will be fine too, but all I'm saying is:
IF the bottom of your precats are missing, then dont start your engine until your sure they aren't going to be in your cat and get sucked into your engine.

Richie

Anonymous · March 27, 2006, 16:00

Chances are though, if the bottoms of them are missing, they'll already be missing by now, and I've been starting my car every day since I bought it (it makes it go quicker s;)

s;) ) so unless I'm missing the point, there's not much I can do at this stage other than have the manifold replaced and see what state they are when they come back.

How easy is it, by the way, to have the garage check the main cat for lumps of pre cat??

Anonymous · March 27, 2006, 16:18

Quote from: "Slurpy J"Chances are though, if the bottoms of them are missing, they'll already be missing by now,

I Don't think they can pass the matrix of your main cat (hence the clogging effect upon failure) so particles generally end up hanging around in the main cat, rather than getting blown out of the exhaust.

Quote from: "Slurpy J"so unless I'm missing the point, there's not much I can do at this stage other than have the manifold replaced and see what state they are when they come back.

pretty much, theres no point going out and buying a new cat until you know whether or not you need one.

All I'm trying to say is, If (when you've removed the manifold) the bottom of the precats have failed, then dont put it all back together using the same cat.

Quote from: "Slurpy J"How easy is it, by the way, to have the garage check the main cat for lumps of pre cat??

TBH, its easier to look at the bottom of the manifold and see if anything is missing.

If you did discover some missing precat on the bottom of your manifold, then I personally wouldn't be satisfied with just shaking out any debris.

Hopefully, the bottoms of your precat will be fine anyway and all of this advice is in vain, I'm just trying to give you a tip to avoid possible failure problems.
Richie

Anonymous · April 5, 2006, 08:19

So I got my old manifold taken off yesterday and the new Che one fitted. The pre cats were absolutely mint.. no scratches, cracks, degredation nothing... perfect criss-cross honeycomb throughout. Pleasing I thought... still glad they are out of the car now, but it just goes to show, even at 65k miles on the clock, you might be ok... it's never too late!