Oxygen Sensor
 

Is there a simple way to test the Oxygen sensor? I'm not a mechanic and have no idea of how to do it.
I asked because my Accord lx 1990 has new spark plugs, air filter etc and fuel economy is dropping. It also has become over some time sluggish, throttle response is sometimes O.K but others is very slow and the car hesitates to accelerate at low RPMs on high RPMs this hesitation is less noticeable. So I suspect of the oxygen sensor.
Any simple advice if it exists will be greatly appreciated, I don't want to spend a lot of money on a sensor and discover that it was not what was wrong. No check engine light as of now. I have replaced that thing a couple of times before, both gave check engine codes, one time was 42 I think, fuel delivery (supply) system and the other was O2 heater or something similar.
At least I own a digital voltimeter which I think is needed for testing the O2 Sensor.

Thanks

well if the o2 sensor has a lot of soot on it will fuck up the readings for the ecu, thus the reduced fuel consumption. what i found out on my car was that the spark plug wired had a crap load of oxidation in them. all i did was clean the insides and put some dielectric grease on it.

hope this helps. also how many miles on the car ?

It is around 130,000 maybe more. Wires are NGKs and are like new, not to old either.
I have not taken the car to a gas analysis, I'm only concerned about this poor performance, when I step on the pedal the car won't respond inmediately and a moment later it will accelerate acceptably. Fuel economy has dropped about 10%. Injectors are clean too.
Could this be related to the O2 sensor? Or could be something else?
Do the tests done to the O2 sensor like varying voltage are done with the O2 sensor unplugged? Does it generate it's own voltage?
The car plug has black, green, white, gray wires (not really sure about the colors, can't remember) what's each wire for? Which one is the signal wire?

BTW from a while ago in the mornings it won't start as fast as always, I have to crank it for about 2 or 3 seconds, before I just turn the key and it instantly started.:confused:

sounds more like a failing coil/igniter to me.

Coil is about 1 1/2 years old and it is an original part from Honda. Could it be fried by now?