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joff-turbo-nova
22-10-11, 05:29 PM
Hi all,

Just taken the exhaust off the Z20LET in the Astra Coupe and I peered down the downpipe into the precat expecting to see a cell structure of some sort and got this view :-

http://i2.photobucket.com/albums/y15/joff-turbo-nova/Exhaust0001.jpg

Its empty and you can see all the way through to where the pipe exits at the bottom.

Is this standard or has someone been playing with this before I got it?

Joff
Mazz
22-10-11, 05:40 PM
honeycomb has been bashed out, precat is not need in the uk iirc
Lewis.
22-10-11, 06:11 PM
it will still pass the emmisions test without it, but the MIL may come on with a ''catalyst efficiency below threshold' code stored in some cases.
John
22-10-11, 06:52 PM
yep someone has removed the middle. As said, not needed in the uk, but eml may illuminate with it removed.
Mieran
22-10-11, 06:58 PM
can space lambda out with a few washers if eml comes on
joff-turbo-nova
22-10-11, 07:03 PM
It was running fine with no ECU lights on, just wondered if this is a normal pipe as it doesn't have a flange below the precat like most of the Z20LET's I've seen .

Its NOT like this ....

http://www.lmfvauxhall.co.uk/image.php?type=T&id=1121http://www.lmfvauxhall.co.uk/image.php?type=T&id=1121

Joff
Mieran
22-10-11, 07:11 PM
How is it connected to the CAT then? Sleeve joint?

I'm sure some coupes didn't have a separate precat, the cat and precat was one unit
Rich
22-10-11, 07:28 PM
Some had an all in one downpipe so the precat wasnt seperate. You wont need the precat for emissions as said and it wont show a eml if you still have the standard cat doings it job.

Definatly been smashed out though, and get you lambda sensor changed! Running a bit lean by looks of that exhaust
Stuart
22-10-11, 07:40 PM
9.9/10 times the precat will NOT trigger the EML. Its purely there to get rapid light off on the NEDC for emissions BS.

Most of the time they cause the cast manifolds to crack, so bin them :)
joff-turbo-nova
22-10-11, 08:12 PM
Some had an all in one downpipe so the precat wasnt seperate. You wont need the precat for emissions as said and it wont show a eml if you still have the standard cat doings it job.

Definatly been smashed out though, and get you lambda sensor changed! Running a bit lean by looks of that exhaust

I think its the LED light making the soot lighter than it really is, its quite dark really in normal daylight.
joff-turbo-nova
22-10-11, 08:15 PM
Some had an all in one downpipe so the precat wasnt seperate. You wont need the precat for emissions as said and it wont show a eml if you still have the standard cat doings it job.

Definatly been smashed out though, and get you lambda sensor changed! Running a bit lean by looks of that exhaust

Yes its all in one ...

http://i2.photobucket.com/albums/y15/joff-turbo-nova/Exhaust0002.jpg

No flange joint ...

http://i2.photobucket.com/albums/y15/joff-turbo-nova/Exhaust0003.jpg

Joff