I6 C280 W202 Running Rich?

[dalmiester]

Hi All

My 1994 C280 M104 seems to be running rich (I think), The exhaust smells a lot which I actually enjoy, It's a reminder of what cars used to smell like. There is no exhaust smoke at all. This problem only occurred after one of the coils blew and I drove the car for about a mile! I have replaced the coil and the car runs fine again.

I have driven it several hundred miles as I assumed unburned fuel may be sitting in the exhaust but I still have the heavy exhaust smell (still no smoke). Also the car idles high after a run (900-1000rpm) it will settle down after some minutes to a more reasonable idle speed. Are these two problems related?

Have I caused damage to the O2 sensor, Cat? something else? When the coil blew and I drove it for a mile or so, the exhaust smoked (like cigarette smoke) for about five minutes after switching the engine off.

Any suggestions appreciated!

Dal

 

[BlackC55]

I expect one of the lambda sensors is kaput. A Star diag machine can check it.

 

[dalmiester]

I'm wondering if for £60ish it's worth just changing the o2 sensor anyway. There is only one isnt there?

Will a new sensor just plug in and work or will it require star to set it up!

 

[Stratman]

Running for an extended length of time with a rich mixture can also cause failure of the catalytic convertor.

An excellent article about cats can be read here.

 

[mjcr666]

what was the car running like before you had the coil replaced ?? sorry but my car has a problem with the way it runs and it could be coil problems.
thanks
mike

 

[dalmiester]

The car was perfect before the coil blew. I changed the coil and its perfect again except now I have the strong fumes.