Poor fuel consumption

[CMF_burner]

Hi guys,
I have a 2000 Micra GX (1.0 litre) UK/Irish make, manual. I've noticed my fuel consumption getting worse. I have read some information in relation to o2 sensors, thermostats, MAF and ECU's on the forum.

Firstly, I have tried the self diagnostic process, I.e: shorting the ECU plug in socket, located at the car fuses. This process (I have followed information from other members of the forum) doesn't work for me. Can the forum give a step by step instructions on the diagnostic process to check the o2 sensor?

Can a step by step process be given on how to remove the 02 sensor. I have looked at it and wonder how a spanner can get access and remove the 02 sensor. Also, can I have advice on how to test the thermostat (linked to poor fuel consumption) with location, tips etc

Thanks for your help

 

[CMF_Micra_King]

Ill explain it so even the most non mechanical minded people can follow.
To test the thermostat just start the car when cold and let it warm up for a minute and then start driving and the temp should rise to around half way (a bit under or over half way is still normal) in 2 to 4 minutes of normal driving and then stay at that position. Even when really cold the temp should still rise and stay in that position. All the thermostat does is stop the water flow from the radiator into the engine until it reaches the correct temp and then it opens. When they become faulty they stay open all the time so the engine never reaches the correct operating temp and this effect fuel consumption and causes higher engine wear.
Not sure on the way some test the O2 sensor but basically if your car has over 80,000km on it then replace it with a new one. Even if the test says its working there's no test to show how efficiency its operating at. To remove it I just use an open end spanner or there are O2 sensor tools you can buy that fit over them and then connects to a ratchet but I found them to annoying to use. If you then replace it with a universal sensor you have to cut off the stock sensors plug and connect it to the new sensor but that's easy to do and most come with instructions on how to do it right. There is no soldering needed as the universal sensor should come with wire crimps to connect the wires together. Then just screw it back in and when finger tight just a small amount of tightening with the spanner. You will find most sensors come with a coating of anti-seize on the thread, Make sure you don't get any of it on the sensor when you handle it as that will effect its performance.
I cant help with the MAF part of your question as its something I have not messed with before.
Hope that kinda helps. Its always easier for me to do the work than explain it

 

[CMF_burner]

Hi-Micra King,
Thanks for the reply. My temp guage operates exactly as you have described, so I don't think the thermostat is faulty. I'll have a go at removing the 02 sensor and let you know.

Thanks for your help