1976 SL Catalytic Converter - PeachParts Mercedes-Benz Forum

eddennis · #1 09-09-2010, 11:40 AM

I am looking at a nice 76 450SL but still has converters under the hood. I would like to eliminate or move downstream.

Questions:

I assume new manifolds will be needed.
Can converters be eliminated entirely (I live in a no smog check area)
What electrical (computer) problems I might run into
Is there a how to anywhere on the web for this conversion?

Anything I forgot?

Thanks in advance for your advice

cth350 · #2 09-09-2010, 07:21 PM

look in the vintage forum for several threads about 280C and 450se cars with reactors. Those big ugly things between the manifolds and the down-pipes of your exhaust.

A new set of manifolds from another 450sl and replacement down-pipes should take care of you.

-CTH

rowdie · #3 09-09-2010, 09:22 PM

They were moved downstream beginning with the '77 model year. The '74 and earlier are hard to find and expensive.

coleyjf · #4 09-10-2010, 01:31 AM

The 107 was designed without Cat's (the UK models never had them and as far as I know neither did the mainland European models) so if you can - take them off

meltedpanda · #5 09-10-2010, 02:31 PM

I dont think you can just trash them, I am not a KJET expert , but I beleive it needs input from the O2 sensor, just not sure if it is north or south of the cats?

cth350 · #6 09-11-2010, 07:02 PM

It's not K-jet, but CIS in 76. There's no sensor. These aren't cats, but "reactors". An earlier, less efficient concept. -CTH

meltedpanda · #7 09-11-2010, 07:04 PM

did not know that, learn something every day!!

thanks

450slcya · #8 09-12-2010, 03:47 PM

Quote:

Originally Posted by cth350

It's not K-jet, but CIS in 76. There's no sensor. These aren't cats, but "reactors". An earlier, less efficient concept. -CTH

Ummmmm...K-Jet is CIS.....

meltedpanda · #9 09-12-2010, 08:44 PM

true, but what I think he meant is this , but you are correct both Kjet variations are CIS ( continuous injection
first generation - KJet sytem
second generation = addition of Lamda, ECU and Frequency valve

cth350 · #10 09-13-2010, 11:10 PM

right. 76 is ultra-simple CIS. -CTH

rs899 · #11 09-28-2010, 10:28 AM

So guys, what year did the 450SL go from CIS basic to CIS lambda? Would be nice to know since dear wife wants one and so far I have failed miserably on CIS lambda on an old VW Cabriolet that has it...

meltedpanda · #12 09-28-2010, 09:36 PM

I am pretty sure late build 76 and on . The Lamda was added along with the ECU , and frequency valve.

alabbasi · #13 09-29-2010, 12:18 AM

Quote:

Originally Posted by meltedpanda

I am pretty sure late build 76 and on . The Lamda was added along with the ECU , and frequency valve.

Actually I think that it was much later then that. If I recall, 1980 was when they added the 02 sensor.

Having an 02 sensor is not all bad, you can use it to set the a/f ratio which is something that you can't do with a CO meter if you have cats in place.

rs899 · #14 09-29-2010, 06:19 AM

I don't know, but 80 sounds more like it to me. VW switched to CIS lambda in 81, and I don't think they would have been 5 years behind the times. I thought I read '76 was the changeover from D-jet to K-jet.

meltedpanda · #15 09-29-2010, 10:24 AM

I was just looking at the engine system design manual, I guess 76 was when the lambda system was available,and not when it went into all of the car lines, my bad, I read the question wrong.
The CATS moved downstream in 77 and redesigned in 80 to the 3 way converter, perhaps that is when the lamda was added, would at least make sense.