I recently inherited a 1980 450Sl with 44000 miles. When I got the car it was a real dog and I (thanks to the mercedesshop tech forum!) traced the problem to a non functioning relay for the lambda computer. I now have plenty of power (all 160 horses) and everything seems to be fine except there is a very strong exhaust smell. Doesn't smell like sulfer, just strong. As near as I can tell the exhaust system, which is the original, has no leaks and nothing wrong that I can see. Since I fixed the lambda I have alson noted that the gas mileage is only in the 13 mpg range. Is the problem that the engine is running too rich and I am smelling the unburned hydrocarbons?
Suggestions would be appreciated!