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Discussion Starter #1
Ive bought this car with an Eisenmann rear(EB5506) en mid(EB 5506 7 1)silencer. The katalitic converter has been removed and replaced with a piece of pipe with only an O2 sensor. The pipe seems to have the stock mounting Flange but im not sure if an stock kat would fit on the same place, ive added a picture. If a stock kat would fit i probably wouldn't be able to find one, ive seen some in germany for 600+ euro and new from the dealer 1600 euro :eek7:.

Ive been think to weld together one myself but i will be needing the correct mounting flanges en pipe diameter for connecting it all together. Does anyone know if there is another exhaust system the uses the same type and size of connecting pipes? Front pipe Diameter is 55mm and to the rear connecting to the middle silencer is 64mm.

The CO has to be 0,5% or less and i haven't been able to get it lower then 1% after some maf tweaking. Im not sure if a new O2 sensor would help enough without a kat. I was planning to replace the O2 sensor after some head work.
 

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Discussion Starter #3
They didn't tell me anything about the other values so i guess they where all within spec.
 

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Is the car from 1993 or before? Before you could remove the lambda sensor/unplug it and tweak the MAF to get under the 0.5% (leaner). But if it is after 1993 it should have the lambda readings and CO % readings within spec which is impossible without catalic converter(s).

You can make a pipe with catalic converter for the MOT (APK) but you will need to replace it every year for this test. €600,- for a complete catalic converter with pipes does sound not to expensive. I don't have anything laying around (allthough we have 2 E34 M5 3.6 running) otherwise we could swap the exhaust, test the vehicle and put it back so you have 1 year of creating a solution.
 

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Interesting to see an Eisenmann middle section, they stopped making them some time ago!

If you are keen to switch it out do send me a PM as I have been looking for one for quite some time.

Hope you manage to solve the issue!

Kind regards,

Lantz
 

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Discussion Starter #8 (Edited)
Thanks for the reply's.

The car got on the road at 30-03-1993 S38B38 but i dont know the exact production date. I could try unpluging the O2 sensor and tweak the MAF but they mechanics already tryed tweaking it with the O2 sensor connected and 1% was the lowest it would go.

@Theodegrote Do u mean the the spark plug socket nr3 12131404101? or the complete Ignition coil. On the 6th cilinder this ignition coil has been replaced with an aftermarket one cant read the brand on my pictures but i will take a look tommoro.
http://realoem.com/bmw/diagrams/l/t/15.png


@Lantz i wasnt planning to replace it soon but my setup as it is now i pretty loud. Its very nice under 3000RPM and almost but over that it becomes a lot louder very quickly. 3000RPM 5th gear cruising at 120km/h with great comfort :).

Edit: @deviltje thx ill save this one as a last resort. I think it would fit cuz only the part numbers of the cat itself are different but all the gaskets are the same for a 3.6 and 3.8.
 

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I could try unpluging the O2 sensor and tweak the MAF but they mechanics already tryed tweaking it with the O2 sensor connected and 1% was the lowest it would go.
Adjusting it while the 02 sensor is stil connected doesn't have any use. The ECU will keep the mixture around lambda 1. When the 02 sensor is disconnected there is no feedback and no adjustment to the injection time wil be made. Only then adjusting the MAF screw has use.
 

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The mechanic put in two new coil packs. I remember reading somewhere that the coil packs can effectively be tested by measuring the resistance over the coil. I do not know the applicable values though.
I hope you solve this problem. I had the they guy that I bought my car of solve the issue before buying. I remember him being mighty frustrated and ending up bringing her to a M specialist dealer. This is where they fixed it for a hefty sum of EUR 1.350. Good luck and let us know!
 

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Ill check tomorrow if we have a cat section for you. We have 2 S38B38's "in stock" so their still might be a cat section left over.
 

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Discussion Starter #16 (Edited)
I went for a MOT retest and i passed the emissions test!!! It was a bit of a struggle to get it fitted on my jack stands because some flanges where bent. I didnt have time to order another O2 sensor so i kept the one that was fitted and i didnt want to take any risks cuz it was my last week for the mot.

At the first test my CO was between 2 and 3 % and with some MAF tweaking i got it to 1% after the test the screw was turned back to its original position. Saturday i fitted the kat and gave it to my mechanic on monday and the CO dropped to 0,35% with NO maf tweaking :D. I guess u really need a working kat to pass any emissions test unless u have a freshly overhauled engine with all new injectors, coils, sensors and the lot.
 

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Got myself a kat from marktplaats ;). I cannot find any info on the partnumbers that are on this cat never heard if the brand Boysen either. Ill fit this tommoro and get it tested on monday lets hope it aint a fake hiha.
Those are genuine 3.8 M5 Kats and you got a bonus O2 sensor thrown in too !!!!!!

D
 
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