Do I need an oxygen sensor?
 

I have a 1987 mercedes 190E, i just had it smogged and it passed, but the hydrocarbons are pretty high. Doing some research online, it said that it may need a new sensor. As far as I know, it;s the original one in there (244k miles)
Is this a fairlyeasy thing to replace?

I'd put a new one in.



given a lot of PB is used, and is soaked in, yes; it's easy.

If it is the original one and still works, maybe you could sell it back to Bosch for analysis on how it lasted as long as it did:)

Your sensor is too old. Change it, emmisions and fuel economy will improve. However, a vacuum leak can lead to high HC readings. Check for a leak first.

Dealer response
 

I just called a local MB dealer to findout what it would cost to change the o2 sensor. I told him that I have 244K and never had it changed. He said that maybe it doesn't need it....bring it in for an estimate, it may be something else.
He suggested a cat. converter. I changed that 2 years ago.
As usual they want me to bring it in to give me a list of work that it needs.
So predictable.

Pb?
 

What is PB?

I am guessing he means lead. Oil consumption can also cause the O2 sensor to become sluggish.

Mike

I am assuming he means a liquid wrench and not lead (e.g., rust away, the spray that loosens sticky bolts). Replace it - you can get it realitvely nexpensive on ebay - you can rent a socket usually from autozone for free. Then all you need is to soak it in for a day (several applications a day_ and have a breaker bar and some muscle.

PB is PB Blaster penetrating fluid.

Liquid Wrench is usless as a penetrant for freeing up rusted fasteners -- it's a good cleaner, and wet lubricant. But when it's gone, so are the lubricating properties.

Several days of multiple applications of PB Blaster can save you a lot of headaches.

Jeff Pierce