o2 sensor question (really simple)

[KA24Power]

In the middle of replacing my o2 sensor on the 240, the old sensor is completely black... what does this tell me about my engine? Can you do the same kind of diagnistics you can with dirty and fouled spark plugs? does this mean that the car has been running rich, as suspected?

Thanks!

[dickie]

wrong forum, moved to KA

[KA24Power]

Thanks d!ck, didn't realize that wasn't really the right forum, my bad.

[WWJD]

umm well to me if that were my car I would think it was badly mantaned. give it a tune up change the o2 then knowing everything is good on the motor ask yourself how it's running? that's the only real way to konw for sure. as for the diagnistics there's a mod on your ECU that will allow you to check your o2 sensor. It might be mod 2...? look in to it

[sideways24d]

how much do a set of 02s cost and is it worth it to find some in the j-yard?

[Moto Man]

how much do a set of 02s cost and is it worth it to find some in the j-yard?

You only need one for your car, and they're not that expensive, so not worth bothering with the junk yard.

If you have a crimping tool, or just a pair of pliers, you can even buy a "universal" one that is cheaper still.

[KA24Power]

Thats what I got, a universal one. I get parts at cost, and it was something like $30 CAD.

The car is running a bit better but I'm getting pretty rough gas mileage.. 400 kms to a tank. I know people are getting 400 miles to a tank.. thats a pretty big difference.

anyone got ideas what to do to help that? I just did plugs, and coolant temp sensor. Should I do air filter, fuel filter, plug wires, cap and rotor? I'm even starting to think I might have an injector thats sticking open, because I can smell the car running rich. It's not blowing black smoke though.

[WWJD]

do a full tune up. when you take out your Spark plug number them you know #1,#2,#3,#4. then go back and study them. they will tell you everything about your injectors. cap & rotor, Plug, wires, fuel filter, air filter. DAM 400 MPG..... I dont belive it...I'm lucky to get over 260 MPG in my heavy SOHC320 MPG in my lesser weight DOHC. and that's pushing my cars....

[KA24Power]

I heard that 350-400 was common? I guess not! that makes me feel a little better..

I'll probably be doing a full tune up soon, and I'll check the condition of my plugs and see what we've got going on.

[0wn3r]

he said 400kms per tank...that's a little less than 250 miles per TANK. not "mpg"...i dont think any 240 (except maybe the electric converted one) gets 4 times what a hybrid will.

what did your plugs look like?

[KA24Power]

didn't take them out yet, its nearly midnight here and the car is still hot, just drove home from work.

[Moto Man]

400 miles per tank is doable, but only with moderate speed highway driving.

400 km per tank is about all you can expect for city driving.

[KA24Power]

Yeah I've come to expect that... its pretty consistent. Doesn't help that you have to pretty much floor it all the time with the a/c on. Stupid little single cam... boost is needed

[WWJD]

I know people are getting 400 miles to a tank.. thats a pretty big difference.

unless it was a type-o

[sideways24d]

didn't know i only had one thats good to know. I thought most cars had an upstream and a downstream? I've never really looked on mine

[KA24Power]

Yeah the 240 only has one, but after OBDII there might be a second one? My car is a '90 so I'm not sure.