thanks,

so what are the thoughts on the smelling exhaust pipe?

If the 02 is old its gone.Change it with a bosch unit.Direct fit for me is best.Never had good luck with with 02s you have to wire.Should be the same but not.Also do not use any other brand other than bosch.Japanse 02's for jap cars only.They are different.
For what it is worth i do 02's every day.I work in a smog shop doing smog repairs only.
Rich

so do you think it is could be responsible for the continues smelling exhaust pipe and bad gas millage ?

thanks,

YES,but to make this easier ,lets say you have a second problem but need to find it.Now your 02 is marginal or even good.My way is to start with a new 02 first as this can make other parts look bad.In the brains of a car the 02 does alot and is a high wear part.80 to 100k on an 02 is alot .Yes some last longer but starting with a new 02 for the most part puts the car in fuel control.Then if something else is wrong you can continue from there. You will find most of the time that the car is ok now.
PS that smell is your cat overheating and maybe starting to melt.
Cheapest part first
Rich
MY 91CE had bad fuel injectors when i bought it and instead of buying 6 new ones i tried to find the bad one.Well ended up replacing injectors to late and my cat is now melted.

why was this moved moderator?

thanks,

hey latief, i was reading up on O2 sensor testing when i came across your post. I happen to have the same exact model benz, US spec 2.8 300E with the m104 engine. replaced the head gasket about 10,000miles ago, but have just recently started paying attention to mpgs.

cold starts for me tend to be around 1100rpms initially and gradually drop to around 800rpms after about 30-40 seconds. All subsequent startups(with wwarm engine) tend to read about 700rpms or so.

the reason i was looking into this is because i too am unsure as to when the previous owner last changed the O2 sensor? just for a reference how many mpgs are you getting from your 300E?

my situation is as follows: driving style = semi lead-foot :) just about 100% city driving, and i only use either 95 or 100 octane gas, and i am averaging about 16-17 mpg. i've even done some research to see what other people are averaging, but the mpg numbers seem to vary too much.

good luck,
tim

A lot.

They are warrantied for 75K miles from the factory because they are vital to keeping emissions down.

A symptom of a bad O2 sensor is excessive fuel consumption.

The O2 sensors tell the engine management if it's getting a good fuel mixture. The default output is to dump fuel.

If you have a bad or dying sensor the car will never run right.

O2 sensors are easy to replace and they should not be overlooked. They will ruin a catalytic converter like somebody has said.

I respectfully beg to differ.

Bosch replacement O2 sensors are notoriously junk.

I bought new ones for my '98 Jeep Cherokee and they were faulty out of the box. I had to get some from the stealership.

Either get the MB sensors or go with a Japanese manufacturer.