Oxygen sensor - when to change / fuel economy

[ZenArcher]

Just wondering what sort of effect a faulty or not working oxygen sensor would have on fuel economy and when should it be changed?

Had my 1.8 conversion done and it is great. But the fuel economy is not so great. Canberra to Sydney I would use a little over 1/2 a tank (according to the guage) with the 1.6 on the way home with the 1.8 I used 3/4 of a tank driving at the same speeds. Just wondering if the oxygen sensor may have given up the ghost after it was installed. It was the one that was used with the 1.6

I believe the diff ratio's were different for the 1.8's compared to the 1.6's but I didn't think I would use a 1/4 of a tank more in fuel. For those of you who have done the 1.8 convesion, what fuel economy are you getting on a trip and around town?

[ZenArcher]

Well, for those who are intersted, I bought a new O2 sensor from Motor Spares here in Canberra cost $79.

I then swapped out the complete throttle body with another one I had - just to make sure it wasn't the idle speed controller playing up. Then checked the spark plugs. Well, they were as black as could be. Same thing again when I removed the OEM O2 sensor - totally black. Installed some iridium plugs and the new O2 sensor once I lengthened the wire long enough.

After letting her warm up I set the idle speed and went for a drive. No more hassles. Idle was perfect and after checking the plugs, they were the proper colour. Best of all, fuel economy is back to normal and power is better as well.

[Astroboysoup]

thanks for that post Zen

I checked my o2 sensor a few weeks ago and it looked fine to me and i think its wprking properly.

might replace when i get my turbo install.. if i do././

[93_Clubman]

good to hear you found a solution...