Pre cats

[Mackie]

2002 mk3 37000 miles
Should I remove the pre cats

[Call the midlife!]

It's a bit of a piece of string question really, if you've got nice clean oil and keep it changed regularly and it's not burning oil strongly then there's every chance you could leave them in place with no ill effects.
You can check the condition of the precats "fairly" easily by removing the O2 sensors and looking down the holes. If you can see nice, intact honeycombs then you're probably good to leave them in place.
And here's where we lead you down the path to an empty wallet...
If you're taking the manifold off to remove the precats then consider spending another £100 or so on a replacement such as a Toyosport instead?

[Mackie]

Thx.
What would you do?
Only 37400 mileage

[Mackie]

Is a toyosport a straight replaciement

[Call the midlife!]

Yup, as long as you order the right one it's a direct replacement, you'll just need some new crush gaskets.

[Ardent]

@Mackie

The general consensus, is don't skimp on the gaskets, go for Mr T's own.

[Mackie]

My dilemma is I have a 2002 with 37000 miles
No probs at the mo
Do I just keep checking the pre cats
Or remove

[Ardent]

My dilemma is I have a 2002 with 37000 miles
No probs at the mo
Do I just keep checking the pre cats
Or remove

I thought I had responded once but maybe didn't press the reply button.
Personally I would leave them alone, if you have no problems now by which I mean you are not burning oil  I would leave them. By all means have a peek at them but be prepared the sensors do not like being disturbed and you may get a code shortly afterwards

[Mackie]

Thanks ardent.
Still in a dilemma
Trying to keep her low mileage
But want the best for her and to enjoy occasionally

[Ardent]

How about leave that one alone and buy another one to enjoy, rather than have an enjoyable car stuck in a garage.

[1979scotte]

I can't see the point of keeping these in the garage.
I honestly think they'll not be worth any money for years and years.
Just not popular enough.
Most people who see them think they're mazda or porsche.
Drive it and enjoy it.
Drive it harder and enjoy it more.

On the pre cat issue.
They need inspecting.
If they're OK and you aren't going to do many miles leave them be.

If you haven't done so change oil and filter.
Also inspect the rear crossmember for corrosion they rust from the inside and low mileage is not necessarily protection. I had a 50k 06 plate that was in a bad way but cosmetically great.

[Petrus]

As observed, it is not a rare gem to be conserved but rather a rare fun car to be enjoyed.

Concerning the precats it is a risk asessment.
The chance of it occurring versus the seriousness of the consequences.
Replacing the OEM one with a reasonable quality tubular is not costly. The precats failing is quite unlikely but the cost is out of proportion.
That is not mentioning the ´value´ of peace of mind.

Whatever you decide; enjoy the car; thát´s what it was designed for!

[Joesson]

There seems to be two posts with the same theme, the other is " Low mileage" to which I responded as follows.



Hi Mackie
I guess that you have read up on here about the damage that the break down of the precats has done to some engines on our cars and hence your question.
You may also be aware that the root cause of the problem is the design of the original oil ways in the pistons and this is exacerbated by irregular oil changes.
As you are at best the second owner the service frequency and regularity of the oil changes may not be known to you.
My suggestion would be, firstly to check the condition of your precats by removing the top two sensors in the exhaust manifold.
I did this and mine were fine but I still went ahead and gutted the OE manifold.
If showing signs of breakdown then I would definitely gut the OE or, as many on here have done, replace with an aftermarket manifold.
My understanding is that the single, most important maintenance of our engines is a regular change of the specified oil and filter.
At least once per year, I cannot recall the mileage as I never reach those figures but nevertheless change oil and filter annually at around 3K.
———————————————
After reading all of my fellow members comments and reconsidering what I did several years ago I would still de cat the OE manifold. Doing so was my first up close and personal visit to the workings of the 2, and you get to have a good look at the crossmember.

 

[ManInDandism]

My own take on the precat stuff - we all have our own opinion    is that whereas there was evidently a design problem that did result in some issues, the problem is widely overstated.  There is also a lot of scaremongering.

I bet 99 out of 100 MR2 owners, the majority and those that don't do forums, are blissful in their ignorance and maintain, drive and enjoy their car just as they would any other vehicle. 

Nearly every half-decent buyer's review mentions this, yet Toyota's seeming reticence to acknowledge an issue is easily backed up by stats...or lack of.  Bearing in mind that it dates back nearly 12 years, I'm even surprised at how few cars there are in the Register at the top of the page.  Don't get me wrong, obviously not nice if it happens to be your car. 

20 cars currently being broken on eBay and I would hazard a guess that most are due to normal end of life issues such as being pranged, left to rot, faulty and expensive to repair SMT gearbox etc.

Not something I'm ever going to be losing any sleep on... 

[Chilli Girl]

Well, I'm on my second MR2 and both had full service history, with annual oil changes from the start, mileage on the first was 70k and pre cats in excellent condition although the new owner did remove them.  My current MR2 is on 65k and they are in the same condition!  My pre cats are staying, only because I know the history of the car and it receives regular oil changes!      That's just my take on it.

[james_ly]

I wouldn't even worry about precats, mine is currently being used as a daily workhorse, 112k miles and running fine..

[Beachbum957]

We have a 2003 that had regular oil changes with synthetic oil, and at 130,000 miles, the precats were perfect.  The manifold was replaced by an aftermarket header for reasons other than removing the pre-cats.

[Ardent]

The above 2 posts, to me, says it all.