Failed MD. emissions with 560SL
 

I live in MD have a 560SL it failed emissions local mechanic says it is a EGR valve. Are they hard to replace?

What did you fail for? Its my understanding that the EGR primarily controls NOX. If you failed for CO or HC, its probably something else.

Max

Max It failed for NOX the reading was 3.7553. Do you know how to change the EGR thank you for your time in replying.

Here we go again with theoretical versus actual knowledge. I've changed EGR valves on other cars, and I can't imagine it would be very different on a Mercedes. I would soak the mounting screws with a PB Blaster or WD-40 first. The actual remove and replace is pretty straightforward, the only issue possibly being accessibility. Make sure you get a new gasket with EGR valve. Also, when the valve is removed, check the manifold port for possible carbon build-up. Clean it up and install the new EGR valve. The emission system should then make whatever changes are necessary from then on.

If anyone else has made this replacement on a Mercedes, please feel free to correct any errors in this narrative.

I can't find the procedure on the service CD, but it does note that this area changed for the 1988 model year.

"The control valve in the vacuum line between throttle assembly and exhaust gas recirculation valve is no longer required as of 09/87. The exhaust gas recirculation valve is connected with vacuum directly only as a function of the thermovalve."

So it makes a little bit of difference whether your 560SL is 86/87 or 88/89.

Stilled failed emissions
 

Got tested third time Still failed on nox it was a lot worse than the last time. When I replaced the EGR valve could I have done something wrong?

Perhaps you should think of more creative strategies regarding emisssions inspections.

Read this thread.

http://www.peachparts.com/shopforum/tech-help/43209-how-do-i-fix-high-nox-levels.html

Failed MD. emissions
 

Richard 1, exactly what do you mean?

failed emissions
 

Go to www.directhits.com
This could very well solve you problem. I have used this product to do just that on other autos. Plus more mpgs, power and torgue.

72 SLC 99,000

TSL,

I am very interested in your experiences with the directhits product. I called the company and talked to their technicial people. It sounds like solid technology. I could not find any holes in the story he was telling. However the proof is in the pudding.

How did it work for you?

failed emissions
 

Hi Dave,
My experience has been nothing but the best investment in my old beast. Except, they had to make special wires with 90 degree boots to clear each other. Simple to put on. Seems to can open gap on plug a little, they supply the plugs and new set of wires. You can advance timming a little by about 3-5 degrees, on any vehicle I have ever put them on in the last ten years, I have seen no less than a 10% mpgs increase and as high as 25%. I have used to past emissions on used autos I purchased for regular day to day driving. A Cressida, Maxima, and Dodge Caravan. When the vehicles were purchased none of them past emissions until I put these on.
Good Luck,
Tim

S Car Go
 

Did you solve the problem yet? By creative solutions, I was making a joke by alluding to some not so legal approaches to your problem...but definitely not worth the trouble.

Failed MD. emissions
 

Richard1, I realized your allusions were to some sort of naughty behaviors regarding the tests! I was just hoping you'd elaborate. Not that I'd ever act on it, mind you; just looking for a bit of education! Guess I'm the naughty one.
Thanks, though, for your reply.
Everybody have a safe and happy labor day - hope ya'll get to go driving somewhere nice in your beautiful cars.