My 1987 300E just failed Maryland emmision control. The Nitrogen Oxide was a bit too high. Car had 3.2 where 2.8 is max permisable. Can anyone tell me what I must do to the engine to bring the Nitrogen down to an acceptable level?

Thanks.

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Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

Chances are you are running a bit lean -- this means higher combustion temps and hence a little more NOx. I'd say you needed to clean the EGR, but you (thankfully) don't have one.

Check for vac leaks -- at this age, ALL the rubber hoses on the engine are suspect, plan on replacing all of them, including the crankcase ventilation restriction. Don't overlook the idle control valve hoses.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks Peter

I just did a search and consequently was ready to go out and ream out the tube to my EGR. I'm glad you told me that the car does not have one. I would have been searching for hours trying to find it in the dark.

I'll do that check on the hoses. What must I do to richen up the mixture a tad?

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Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

If a vacuum hose is leaking, you're sucking in air, thereby leaning out the mixture.

Replacing a leaking hose would eliminate this problem and therefore "richen" the mixture.