M119 Question
 

I replaced the plugs and wires on the 500E today. Everything went smooth, but I had a question.

The plugs were in good shape, electrodes were clean. Each plug I removed had a strong gasoline odor, to the point I am wondering if the engine is running too rich. Idle is smooth, no rough idle. Car seems to run strong. No smoke from the exhaust. Any ideas? Could it be I need a new O2 sensor?

Black, sooty plugs indicate the car is running too rich. If you need an O2 sensor your "check engine" light should come on.

i agree with the above
 

post. he didnt say it but he thinks your car is ok...i think.

if it runs strong and gets good mileage and doesnt miss or anything, then the smell of gas seems unimportant.

tom w

gas smell on plugs
 

A gas smell on the plugs could be from a very immediate recent condition, like I drove 1.5 miles to the grocery store and back in 40 degree weather. The car never warmed up, sure it's running rich. for that trip only, not necessarily in general. I read that a good way to judge plugs for mixture at WOT is to drag race the car and turn it off just past the end of the 1/4 mile strip, careful you may lose some brake vacuum, then pull the plugs.