Precat removal - How I did it...

[Gif]

 s:D s:D    s:D s:D    s:D s:D  

You guys(gals - no idea which you are) are awesome.  The third amigo is toast and the stud is intact!

Thank you Mr Irwin   s:D s:D

[Gif]

 s:bounce: :bounce: s:bounce:  

There's an MR2 exhaust manifold on my garage floor!

[Gif]

Thought I would report back that thanks to a new band of Amigos from Mr T and a lot of huffing and puffing (from me, not the exhaust) the whole thing is back together and operational again.  s:D s:D  

Thanks to everyone who helped with advice and tips.  Would have been up the creek without a paddle.  As it is I am now up the motorway without a pre-cat.  Here's hoping it is plain sailing from now on.

[BEN99W]

Well I did my precats at the weekend after a sudden rattly noise started up from the exhaust.

I had to use a slightly different technique. Being 8 years old, the nuts holding the heat shields on were impossibly corroded - a 12mm socket just span on the bolts. The only way I could get them off was to hammer an 11mm socket on with a club hammer. That did the job on the top two shield-retaining bolts but the two further down did not have the clearance to get a hammer to. The only thing I could do was remove everything in the way. So off came the bumper, the rear lights, the exhaust and the rear cross member.

With room to swing the hammer, the heat shield was quickly off and the o2 sensors could be removed with a spanner rather than the 02 tool which I don't have.

Unfortunately the manifold bolts were equally corroded. However with all the clearance I could see that the manifold didn't actually have to come out to gut the cats.

That was the good news. The bad news was that one of my precats was totally missing  s:shock: :shock: s:shock:  the other one was perfect. When I shook the exhaust about, great big lumps of precat came out - that wouldn't have been doing the performance any good. and I hope was the cause of the rattle I'd heard. I only hope it hasn't already done engine damage.

It did take about 4 hours to do this way, but wasn't actually that complicated a job and can be done without special tools. If the cats have started to go, it allows you to get the debris out of the exhaust too.

Now I've just got to keep an eye on my oil level and keep the fingers crossed.   s:? :? s:?  

Cheers

Ben

[markiii]

if you guttted them with teh manifold in place I hope you blocked teh exhaust ports and washed everythingout throoughly otherwise you just created the problem you were trying to avoid

[BEN99W]

if you guttted them with the manifold in place I hope you blocked the exhaust ports and washed everythingout throoughly otherwise you just created the problem you were trying to avoid

Hmmm Well I didn't do anything to block the ports but I was careful to only push the debris downwards and I did clean it out throughly afterwards. Any dust I might have created pales into insignificance compared to the one entirely missing cat. Still I will be watching it very closely over the next few weeks.

[Anonymous]

I didn't do anything to block the ports but I was careful to only push the debris downwards

This is not a recommended procedure. No matter how corroded the bolts are, they must be removed and replaced with new.

More worrisome is the missing precat. We know where it is - it's firmly lodged in your main cat and is causing a restriction, which is causing oil to push against your rings. This is what causes precat failure death syndrome. At the very least you need to remove and clean your main cat, but the smart thing would be to replace it. There may still be time to dodge the bullet.

[BEN99W]

I did remove the cat and was able to shake a lot of ceramic debris out of it. But i fear I was too late anyway. Oil use seems to be significant and now an engine light has come on - presumably a sensor fault.   s:( s:(  
What's the cheapest solution to getting this resolved? I'm not interested in upgrading to a bigger or more powerful engine (it's my girlfriends car anyway). It's a 2000 model, so well outside the period of Toyota's replacement timescale.

[dipper84]

Guys, I recently removed my precats... took all of 2 days to grind off the b*&&dy nuts. Recently the oxygen sensors have been playing up, i am getting a reading of P0141 Any suggestions? could i have damaged them while taking them out, i treated them like glass but are they that friagile?
I have noticed a nicer rooar when heavily accelerating since the removal, is this common... fair play its a really nice noise!

[roger]

P0141 is the sensor heater malfunction on the one after the main cat - so you shouldn't have harmed that. It only checks the emmissions so no great problem.

And yes, no precats does produce a much nicer sound   s:wink: :wink: s:wink:

[dipper84]

emissions?! bummer!! will this effect its MOT??? ive got a new sensor ready to be fitted so ill pop it in tonight and hope that will solve it. i think it could be where i grinded the bolts off the cat - exhaust pipe and probably damaged the sensor in the process? ill keep you posted on the results of fitting the new one.

  s:shock: :shock: s:shock:    s:scared: :scared: s:scared:

[dipper84]

just another thought (which could be crucial) is i keep getting a p0135 too, so could this mean the engine is running rich as the o2 sensor is dead, creating nore emissions causing code P0141? or is that a dead sensor rather than an incorrect reading?>

[anthony82]

Replaced my manifold yesterday and it was a pig! Main problem was removing the top heat shield so I could get access to the manifold engine mounting studs because all the screws had corodded leaving no real head to put the socket onto. Ended up drilling the heads off and bending the heat shield out of the way to get in.

After that, it was fairly straight forward just needed a long bar to get the leverage to undo everything. I had already removed the pre-cats from a second hand manifold so armed with new gaskets it didn't take too long to get it all back together again. Ran out of time so haven't had chance to start her up and test for leaks yet, but keeping my fingers crossed!

With regards to heat shields, are they essential to put back on to prevent damage to bodywork etc? The lower one fitted to my manifold has corroded badly around one the mounting holes so is no longer fixed with the screw so may start to vibrate. Left it for now, but only option is too remove or replace with new. Any ideas on cost?

[catkins]

Dragging this up as the first post is VERY helpful.

My 2 has done just over 80k miles but I havent a clue whether its pre cats have already been removed (I'm hoping they have for my sake).  It's a 2001 Y reg.  

My sister in law bought a 2000 reg MR-S 4 years ago and hers WERENT removed, even at 60K miles!

How long do they normally expect to last??

Primarily, my question is, how exactly can I check them myself?  I'll admit, being a woman, cars have never been my strong point or a source of interest, however since having my 2 I've made an effort to take time to find out things about how the car works and performs as well as the aesthetics of it.  My partner and his dad are pretty good with cars and refuse to pay a garage for anything less than an MOT lol.  His dad removed his sisters pre cats when she got her MRS but I'm hoping my partner and I can have a look, and if need be, remove them without having to take some of his precious time.

Does anyone have any pics of before/after and where/how I need to be looking to check their position and condition.

Many thanks all

This SEARCH facility really is handy!    s:bowdown: :bowdown: s:bowdown:    s:lol: :lol: s:lol:  

  s:bounce: :bounce: s:bounce:  I love this smiley.... RANDOM!

[ad_car_08]

catkins - What you'll need to do is get hold of an oxygen sensor socket. It's dead easy to recognise, it looks like a deep spark plug socket, but with a section out of the side to allow the wire to poke out the side. When you get one, all will become clear   s:wink: :wink: s:wink:  

Here's a piccy -

Then what you need to do is open your boot lid and you'll see your domed manifold heatshield directly infront of you. Coming out of each side of that is your oxygen sensors. Use your new socket to unscrew them, grab a torch and have a gander inside the manifold - you should see a white honeycomb intact. Replace the sensor and do the same for the otherside.
IF your white honeycomb is broken or there's a size'able hole in it, it tends to mean bad news.

A more comprehensive walkthrough with pictures is somewhere on the forum if you search, it's talked about often enough!   s:lol: :lol: s:lol:

[catkins]

Thanks for that   s:D s:D  

Yeah I have done a bit of searching and found bits and bobs - all very handy!! I think my other half knows where he is looking so will try and do it this weekend.  


I would hope and assume mine, a 2001 plate having done almost 90K, would have already had them removed.    s:shock: :shock: s:shock:  

I hope!

[Anonymous]

Unless the car has been owned by a previous club member it is highly unlikely the pre cats have been removed. However no need to panic as plenty of cars have done this mileage and higher with no problems.  s:D s:D
However, be pro active and whip those bad boys out Clare.

Russ, don't even think about it.......................  s:lol: :lol: s:lol:

[ad_car_08]

Yeah, I bought mine with the best part of 90k miles on the clock. The owner hadn't a clue when I asked about the precats, and sure enough when I checked, they hadn't been taken out.

2 years later, I don't seem to be doing too badly   s8) s8)

[JohnB]

I removed the pre-cats on my lasses 05 plate 2 on monday.....I'd checked them when she got the car 5 months ago, they looked tiptop but having read all the info on here I was always gonna remove them soon as I got 5 mins.

My mate has a garage and gave me use of a ramp for an hour.......top heat shield bolts had to be removed with the grinder, everything alse was a doddle.....the 3 amigos came out no trouble at all....I'd taken the precaution of having new ones just in case but didn't need them.....plenty of plus-gas before hand did the trick.
The cats were still in excellent condition, no signs of degradation.....the car has 42k on.
I completely removed the top heat shield bolts from the manifold and welded new bolts in place....new manifold/head gasket and 2 new manifold/downpipe gaskets...all boxed back up....job's a good un.  s:D s:D  

Thanks for posting the "how to".  s:wink: :wink: s:wink:

[catkins]

catkins - What you'll need to do is get hold of an oxygen sensor socket. It's dead easy to recognise, it looks like a deep spark plug socket, but with a section out of the side to allow the wire to poke out the side. When you get one, all will become clear   s:wink: :wink: s:wink:  

Here's a piccy -

Then what you need to do is open your boot lid and you'll see your domed manifold heatshield directly infront of you. Coming out of each side of that is your oxygen sensors. Use your new socket to unscrew them, grab a torch and have a gander inside the manifold - you should see a white honeycomb intact. Replace the sensor and do the same for the otherside.
IF your white honeycomb is broken or there's a size'able hole in it, it tends to mean bad news.

A more comprehensive walkthrough with pictures is somewhere on the forum if you search, it's talked about often enough!   s:lol: :lol: s:lol:

Thanks for this info.  Just a question though.  Is the oxygen sensor likely to break if I try removing it?  I've had it break on my Punto when the garage went to replace a section of my exhaust and it ended up costing me an extra £70 to have it fixed.  OR, might the manifold bolts corroded and therefore likely to shear?

eurgh.... my partner reckons it "sounds like a nightmare" and we are more worried about other things around it breaking in the process of looking and potentially removing the precats.  My girl has had three previous owners, all female, and by the sounds of it from the people I bought it from, all unlikely to have been club members.  So its highly likely the buggers are still there.

[K T M Rider]

just gutted mine (2000 W  with 98k miles) will do a more detailed post in due course.

Is the oxygen sensor likely to break if I try removing it?  

No. Perhaps the one on your fiat was more exposed to road salt and had therefore corroded solid. the sensors on the '2' are fairly well protected from the elements.

OR, might the manifold bolts corroded and therefore likely to shear?

Given the age of your car it is possible that one or more of the manifold to cat bolts will be awkward to remove.

eurgh.... my partner reckons it "sounds like a nightmare"

Even for someone with reasonable mechanical aptitude who has access to a decent range of tools, it can still be a bit of a hassle I would agree, but nothing like the hassle of what might happen if you leave them in.

The idea of having to spend a grand on a new engine for a car I've barely driven    s:scared: :scared: s:scared:  was my idea of a nightmare!!!

[catkins]

Thanks very much for the reply.

I do appreciate that the hassle of the checking, even if they are not there, is less hassle and expense than risking it!!  Just wanted to check really before we went ahead with it, thinking we could do it in a few hours and be on.  I can't be without a car as I travel a lot with work so the thought of something breaking and me having to arrange to get to a garage is more what Im worried about in the short term.  

I guess we will have to put a date in our diaries to do it on a Saturday morning and when we are not busy on the Monday (and that I have just been paid   s:lol: :lol: s:lol:  ) so that if anything does need more time and expense, it's not going to be a panic job.

PIcs would be greatly appreciated.  It looks like the pics on the first post of this thread dont work any more   s:? :? s:?

[K T M Rider]

took some pics, will upload in the next few days.

First things first, buy the socket, you can get one here:

 m http://cgi.ebay.co.uk/DRAPER-55540-LAMB ... 1098wt_706 m

and if you're very lucky you wont see any white mesh (the precats) when you shine a torch down the holes.

On the assumption that they are still there (and given that unlike me you don't have the use of another car) I strongly suggest that you either get a second hand manifold or go for a new 'che' manifold. This is because I found that easily the worst part of the job was not getting the manifold off the car, but preparing the manifold for re-use (specifically replacing the 3 mani to cat studs, as none were re-usable on my manifold).

Say you go the s/h manifold route - then obviously any time you may need to spend prepping it (i.e knocking out the pre-cats and  /or replacing mani to cat studs) can be done at your leisure without interfering with you using the car.   s:wink: :wink: s:wink:

[uktotty]

But if you do it that way you need 2 gaskets

[K T M Rider]

er, I count 3 actually (2 mani to cat and 1 mani to engine)   s:wink: :wink: s:wink:  

But yes, I recognise she would need to buy a new engine side gasket, but presumably this would cost alot less than the manifold anyway (new or s/h). She said she needs her car, whereas mines just an occasional toy so I could put up with the hours of swearing at my ugly stock manifold.

To be fair though, i would have got there quicker with a mains drill instead of my battery powered crap 'n' decker that lasted about 15 mins between charges................  s:roll: :roll: s:roll: