getting a MK3

[usergoeshere]

Thinking about getting an pre-facelift MK3 now. I have read the guides on MR2roc and advice given here previously.

Is extreme oil consumption the only give away of a pre-cat failure? When viewing a car what else can I check to determine if the pre-cats are failing and going back into the engine? I cant open up someone elses car and start checking the pre-cats so is there any other way? My current 14 y/o car uses around 100ml per 1000 miles so I wouldn't be surprised if the pre-facelift mk3 uses oil too but how much is too much? I read someone's car was using 400ml per 1100 miles and the forum members said its within limits. Where can I find these limits?

Also this will be my first purchase without help so any advice is greatly appreciated.

The car is high mileage but has full service history. I read that usual mileage for pre-cats to go is around 40,000 miles but this one has made it to 115,000 miles so if the pre-cats were to go wouldn't theyve failed by now?

Thank you.

[Essex2Visuvesi]

As a MK3 owner I went for one of the decat manifolds, the precats are not required in the UK, and will easily pass emissions without them.

Also Check the rear crossmember carefully for rust

[usergoeshere]

As a MK3 owner I went for one of the decat manifolds, the precats are not required in the UK, and will easily pass emissions without them.

Also Check the rear crossmember carefully for rust

I know I read that the pre-cats were only required for the US market but I want to know other than oil consumption how can I tell if the pre-cats are failing on a car that I am looking to buy?

[Ekona]

Pop the O2 sensors out and take a look at the top of them. Not infallible as they can crack from the bottom up, but it's the best you can reasonably do.

[JohnnyC]

Pop the O2 sensors out and take a look at the top of them.

I think if I were selling a car, I'd tell anyone turning up with a bag of tools to kindly go away

[mr2garageswindon]

If the pre cats fail they generally block the main cat resulting in sluggish to rev up etc.
I have heard plenty of people worried about the pre cats being sucked into the engine.. how could they get sucked in thru the exhaust? The exhaust blows out the spent gasses,it doesn't suck them in.

Ask the owner how much oil it uses and if the pre cats have been gutted out.

[Ekona]

I have heard plenty of people worried about the pre cats being sucked into the engine.. how could they get sucked in thru the exhaust? The exhaust blows out the spent gasses,it doesn't suck them in.

Man, I hope it's not mk3s you work on!

From the MR2-ROC sticky on precats:

The 1ZZ-FE engine (Toyota’s designation for the engine inside the MR2 Roadster) is a very clever piece of kit, and arguably its main party piece is the VVTi, or Variable Valve Timing Intelligent. This increases engine response all over the rev range by altering the timing of the cams, allowing for differing amounts of valve overlap in order to give great low-down torque as well as good top-end power. The 1ZZ also uses it's VVT to perform EGR (Exhaust Gas Recirculation) functions without the aid of a specific valve like other cars. Under certain operating conditions (usually steady cruise) the cams are timed to scavenge some exhaust gas back into the cylinders, as a way of reducing the high hydrocarbon emissions that modern petrol engines generate at certain times.

[mr2garageswindon]

I have heard plenty of people worried about the pre cats being sucked into the engine.. how could they get sucked in thru the exhaust? The exhaust blows out the spent gasses,it doesn't suck them in.

Man, I hope it's not mk3s you work on!

From the MR2-ROC sticky on precats:

The 1ZZ-FE engine (Toyota’s designation for the engine inside the MR2 Roadster) is a very clever piece of kit, and arguably its main party piece is the VVTi, or Variable Valve Timing Intelligent. This increases engine response all over the rev range by altering the timing of the cams, allowing for differing amounts of valve overlap in order to give great low-down torque as well as good top-end power. The 1ZZ also uses it's VVT to perform EGR (Exhaust Gas Recirculation) functions without the aid of a specific valve like other cars. Under certain operating conditions (usually steady cruise) the cams are timed to scavenge some exhaust gas back into the cylinders, as a way of reducing the high hydrocarbon emissions that modern petrol engines generate at certain times.

Lol yeah I do as it happens.
I don't care what some people say. It will not suck back enough to suck the precats into the engine. I have never seen pre cat material in the head or down the bores when stripping one.
Pre cats really ain't the nightmare everyone goes on about.
Oil consumption is a problem if its excessive.

[excalibur1814]

I've had 4 Mk3 MR2 models, all different years, including 2 from 2004. ALL of them have used oil. Every single one.

The pre-face lift model, at 35,000 miles, had the pre-cats removed yet STILL eat oil approaching 68,000. Yay.

[Jaspa]

The pre-face lift model, at 35,000 miles, had the pre-cats removed yet STILL eat oil approaching 68,000. Yay.

my 2000 PFL with 100k has no oil consumption at all. Even pushing it over the alps and the occasional track day and I've not had to top up in between servicing.

Stuart

[excalibur1814]

The pre-face lift model, at 35,000 miles, had the pre-cats removed yet STILL eat oil approaching 68,000. Yay.

my 2000 PFL with 100k has no oil consumption at all. Even pushing it over the alps and the occasional track day and I've not had to top up in between servicing.

Stuart

Then you're damn lucky.

My current 2004 is eating the stuff right now and had the pre-cats removed early in its life. Or Am I doing something wrong?!

[mr2garageswindon]

How can removing pre cats from exhaust stop oil consumption...?
It can't.
Pre cats break up due to prolonged running with a misfire or huge amounts of oil passing the rings and being burned.

Shame they are such a pita to top up with oil without a funnel or removing the rear brace.

Keep topping it up and driving it. If it eventually goes bang, V6 time...

[MilesH]

How can removing pre cats from exhaust stop oil consumption...?
It can't.
Pre cats break up due to prolonged running with a misfire or huge amounts of oil passing the rings and being burned.

Shame they are such a pita to top up with oil without a funnel or removing the rear brace.

Keep topping it up and driving it. If it eventually goes bang, V6 time...

I'll drop off a mk3 with you mate and you can drop me a V6 in it!

I'm sure I can find a car lying around lol!

[Ekona]

Precats can break up with no oil passing or a misfire in sight. Toyota used cheap ceramic material, it's quite happy to break down with no outside assistance at all.

My first car (post facelift) had the precats break up within 10k miles, and then when I had the manifold changed under warranty the brand new set had decided to crack within 30 miles, from my house to a mate's where they were promptly gutted.