E30 Zone

Firstly the car:

K reg '92 e30 318i cab with an m42 IS 16v lump


The old exhaust:

M42 is manifold 4->2->1. Cut from the bottom of the single pipe and welded to the original 318i cat/center section and rear silencer


The Problem:

Everytime i get a quote, using my reg, i keep getting e36 318i systems with the massive rear back box withe the twin bolt square rubber mount.

I have messaged an ebay seller who says this is the correct item
Item: 380478905415
But in the description it says for an e36 an the pic shows an e36 back box


What i want:

Im looking for an original '2->1, cat/center section' and 'rear box'
I know im going to have to cut the new section to weld it to the m42 manifold, but i just need new cat, rear box and pipe work.

Will the above item fit/is it correct? Or can some one point me in the right direction. Thanks

You don't need a cat section. For Mot purposes, your car will be tested with the pre cat emissions test due to either the age of the engine or the fact there were no E30 cabs built with the M42.

That exhaust above is an E36 one by the description, so won't fit your cab.

As you don't need the cat (have you got the lambda sensor fitted with the M42? ), you can use a normal E30 318iS exhaust - I'm using exactly this in my 93/94 touring with the 16v lump.

Lump wasnt registered by old owner, so its still going to need a cat for a '92 318i engine, that why i wanted a new cat and new rear box

I was sure that ebay item was wrong. Thank you very much.

Jus need to find the correct cat and rear box now. Any ideas?

And no, i havent got the sensor plugged in on my car atm.

Does NOT need a cat., engine change registered or not, and whatever your tester says.
Does need the lambda sensor plugged in, unless it has been fitted with an AFM with a CO pot., and the wiring switched to suit.
Order your exhaust for an early E30 318iS.

DaveyB wrote:Lump wasnt registered by old owner, so its still going to need a cat for a '92 318i engine, that why i wanted a new cat and new rear

Doesn't need to be registered. None of mine have and they haven't been cat tested.
My tourings last Mot was with its original 93 318i engine but no cat - I told the tester the engine was from an 89 318i and it got tested with the pre cat test.

Yours should be tested with the pre cat test as it has a 90/91 engine, but also because it has a non standard engine fitted (there were no M42 Cabs built by BMW), regardless of the age of the car.
That's how my 93/94 touring will be tested (without cat) even though both car and engine are post 93.

DaveyB wrote:And no, i havent got the sensor plugged in on my car atm.

It's very likely your existing cat is screwed in that case, and a new cat won't last very long either.

i thought cars made 1992 onwards had to have a cat? that's what mine and davey's friend told us (and he's an MOT tester)

K plate is 92-93

The_Haywood wrote:i thought cars made 1992 onwards had to have a cat? that's what mine and davey's friend told us (and he's an MOT tester)

K plate is 92-93

This is what ive been going by and why ive been trying to match the exhaust/cat to the reg plate

Cars from Aug 92 do need a cat, unless the engine is a pre Aug 92 engine or a non standard engine for the car - there were no 16v Cabs made, so is a non standard engine. Same goes for M50/52 conversions etc.

Mine is a 93 touring with a 99 M44 and will be tested with a pre cat test due to no 16v E30 tourings being produced - confirmed by my Mot tester.
Brianmoooore has posted a link on the zone somewhere that shows the relevant section of the Mot regs.

http://www.motinfo.gov.uk/htdocs/m4s07000309.htm
I have a couple of mates who are fully qualified MOT testers and neither of them are familiar with the deeper recesses of the regs., such as this.

the bosal catalogue online is a good reference, i use it all the time to check the person on the phone i'm ordering from knows exactly what part of the exhaust i'm talking about

http://www.catalogue.bosal.com/pages/ex ... search.php

Brianmoooore wrote:http://www.motinfo.gov.uk/htdocs/m4s07000309.htm
I have a couple of mates who are fully qualified MOT testers and neither of them are familiar with the deeper recesses of the regs., such as this.

Seems pretty conclusive to me,no 16v touring produced,so no cat needed.

When ordering anything from ECP/CP4L/GSF, it's a good idea to use a pre E36 date of production.

This back box any good


********Shameless plug*******
http://www.e30zone.net/modules.php?name ... c&t=241021

When i got for an mot. The emisions require a cat

Thats why im looking for a center piece with a cat and the original back box tonpass emisions

And all that 'non standard engine' stuff had to be wrong. You cant put on old lump in a new car and expect mot test to just allow higher emisions, or expect them to know if its anon standard engine thats not been registered

DaveyB wrote:When i got for an mot. The emisions require a cat

Thats why im looking for a center piece with a cat and the original back box tonpass emisions

And all that 'non standard engine' stuff had to be wrong. You cant put on old lump in a new car and expect mot test to just allow higher emisions, or expect them to know if its anon standard engine thats not been registered

What you have been told in this thread is correct, with Brian even quoting the MOT handbook!

The regs will be applied based on the oldest part of the car, I previously had a 1994 touring with a 1990 M42 engine, and it had a pre-cat emissions test at MOT.

If you put a 1950s engine in a brand new car the only emissions test would be a visual smoke test.

Find a new MOT tester maybe.

mr_dink wrote:

DaveyB wrote:When i got for an mot. The emisions require a cat

Thats why im looking for a center piece with a cat and the original back box tonpass emisions

And all that 'non standard engine' stuff had to be wrong. You cant put on old lump in a new car and expect mot test to just allow higher emisions, or expect them to know if its anon standard engine thats not been registered

What you have been told in this thread is correct, with Brian even quoting the MOT handbook!

The regs will be applied based on the oldest part of the car, I previously had a 1994 touring with a 1990 M42 engine, and it had a pre-cat emissions test at MOT.

If you put a 1950s engine in a brand new car the only emissions test would be a visual smoke test.

Find a new MOT tester maybe.

Yea but my engine is not registered to the car, so surely the mot will be on the specs of a 318i engine (with cat)

DaveyB wrote:

mr_dink wrote:

DaveyB wrote:When i got for an mot. The emisions require a cat

Thats why im looking for a center piece with a cat and the original back box tonpass emisions

And all that 'non standard engine' stuff had to be wrong. You cant put on old lump in a new car and expect mot test to just allow higher emisions, or expect them to know if its anon standard engine thats not been registered

What you have been told in this thread is correct, with Brian even quoting the MOT handbook!

The regs will be applied based on the oldest part of the car, I previously had a 1994 touring with a 1990 M42 engine, and it had a pre-cat emissions test at MOT.

If you put a 1950s engine in a brand new car the only emissions test would be a visual smoke test.

Find a new MOT tester maybe.

Yea but my engine is not registered to the car, so surely the mot will be on the specs of a 318i engine (with cat)

Your car (as original) needs to have a cat fitted to pass the emissions test, yes. But now you have a 90/91 engine fitted (which pre dates the cat test), your car no longer needs a cat test. It can also be tested to the pre cat test as it has a non standard engine. Either reason is enough for the tester to test it with the pre cat test.

The engine swap doesn't need to be registered. The test is done on what is presented to the Mot tester - if he sees a non standard engine or older engine fitted, then he tests to the non cat emissions test... Of course you may need to explain to the tester that the E30 Cabs were never fitted with the M42 engine. If he tries to tell you otherwise, find another tester.

mr_dink wrote:

DaveyB wrote:
And all that 'non standard engine' stuff had to be wrong. You cant put on old lump in a new car and expect mot test to just allow higher emisions

If you put a 1950s engine in a brand new car the only emissions test would be a visual smoke test.

Not quite a brand new car. Cars after Aug 2002 have different regs again.

In this case, a 92 Cab fitted with a 90/91 M42 engine will be tested with a non cat test - I guess I should say, providing you tell the tester what age engine is fitted.

YOUR CAR SHOULD BE TESTED TO THE OLDER NON-CAT LIMITS (3.5%, 1200ppm.) This is what the MOT test regs. say, and if the tester doesn't know this, print this thread off and show him.
You don't need to tell the tester what age the engine is in this case, because it is a non standard combination - a UK E30 cab. with a M42 engine.
Follow the flow chart in the link I gave you, and see where you end up.

Ok well all this has helped alot. Thank you all very much. I appologise for the confusion my end with mot laws etc.

But im still in need of an exhaust lol, so im guessing an m42 (is) exhaust will suffice?!

Thanks again

As Brian said, even some Mot testers aren't totally aware of all the regs. If you have any problems when it comes to Mot time, show them the page of the Mot regs with the flow chart that Brian linked to above.

DaveyB wrote:But im still in need of an exhaust lol, so im guessing an m42 (is) exhaust will suffice?!

Yup, that's exactly what you need.

jmc330i wrote: Yup, that's exactly what you need.

With the proviso that you will need a boss for a lambda sensor (but not a cat.), if your car already has one, OR you will need an AFM with a CO adjuster pot. (the pot. was deleted on late E30s, since it was redundant when all production had cats.), and need to check that it's connected.
Lambda boss (thin M18 nut) can be welded to one of the downpipes, just before the bend where it turns horizontal - that's where I fix them on LPG conversions.

I've not seen a 318iS fitted with a lambda sensor (or cat) in this country. I was thinking the car in question would of had a complete conversion, including the M42 AFM with CO adjustment pot, so no need for the lambda sensor.

Thanks guys - much appreciated!!!