I have an 87 300E wish 195k miles and I failed emissions in CT so I had to take it to a garage to figure out what the problem was even though I hate using garages. The HC limit is 220 PPM and I got 205 at cruise (pass) and 224 at idle (fail). The CO% limit is 1.2 and I got 4.45 at cruise and 3.4 at Idle (both fail). So the garage could not figure out what was wrong and that cost $144 so they did an injector flush which cost $112. They did tell me this may not fix it but after it was done they had me pick it up so I assumed it was fixed. When I took it for the retest I passed HC levels but failed CO with a 3.57 cruise and 1.62 idle. The shop did tell me that my exhaust temp going into cat was the same coming out which they say says not reaction is taking place as temp should go up coming out of CAT. So I was going to get a new Catalytic Converter and muffler and do the O2 sensor with the Bosch p/n - 13953 for the 1990 Ford Mustang V8 302 as shown in this forum:
http://www.mbworld.org/forums/showt...ghlight=exhaust
So will this fix the problem. The car has good power but does make some weird noises mainly what sounds like a lose heat shield when the car is in drive but not moving. The noise goes away if you rev it up a little even if holding the brake so the car doesn't move. It is coming from under the valve cover and is not a heat shield. Anyways what CAT and muffler should I buy? I was looking at these:
http://www.autopartswarehouse.com

1987 Mercedes Benz 300E
Catalytic Converter
Brand: DEC
Note: Direct Fit Catalytic Converter Unit
FITS SKU PRICE QTY
MB2212 $288.40

1987 Mercedes Benz 300E
Muffler
Brand: Bosal
Note: Direct Fit, Rear Muffler, New Muffler, Installs With Simple Hand Tools
FITS SKU PRICE QTY
BO278195 $214.26

Similar stuff at this website as well:
http://replacement.car-stuff.com

I usually buy from Autohauz but the CAT is $900 there!
Would this replacement exhaust be good enough? I can't afford anything performance and they say that they are OEM so??? Any help would be greatly appreciated as I want to order ASAP so I can get my CT plates.

 

why not just adjust the CO down to 1.0 ppm?

 

I don't unerstand...the CO reading was from the emissions station.

 

I think he is talking about the CO adjustment on the car. [&:]

 

I would love to do that, but as far as I know there is no ajustment on my car...at least I see nothing about it in the Bentley bible. Thanks for the replys though...better than the 0 responses I am getting in my other forums that I normally used.

 

Sleepwalker works for Mercedes-Benz i would say if he says it ur car has it.

 

OK I see what you are talking about from this forum:
https://mercedesforum.com/m_33927/mp...t/tm.htm#33984
And info on page 177 in the bible
So on my car I see the stem coming out of the mixture control unit next to the fuel distributor (center of pic) and there is a small hex screw looks like a T8 but the stem is so narrow I need to get a thinner screwdriver. So I am worried that if I failed CO at idle and cruise adjusting this will not matter for idle but I will do it, however how much do I lean it out sense I don't have a way to measure CO while adjusting. How many turns? All the way CCW? Or should I take it to a shop while I adjust it so they can measure CO? Thanks so much for the help!

[IMG]local://upfiles/10842/85FACFB963B34FDE8221E75837CF8F1F.jpg[/IMG]

[IMG]local://upfiles/10842/80CBDA6330804234869851CD57D77676.jpg[/IMG]

 

i could be wrong but i believe that is the mixture screw.

 

best way.

 

That did it I passed. Thanks!