Changed my O2 sensor today.

[redbull]

Gas mileage had gone down in the last month. Started noticing a loss of power. Also I discovered during a short highway trip that I'd have the pedal down pretty far, and when I'd back off, the Jeep would accelerate. I had the catalytic replaced, it was broken up inside. I thought maybe it was clogged and causing the mileage/power loss.

Then I noticed how black my tailpipe was. Quite a lot of soot. Maybe it's running rich? So I picked up a new O2 sensor. No codes, but I thought changing the sensor I had couldn't hurt. Surprisingly it was a 5 minute install, the old one came out easily.

So far, on the same stretch of road the Jeep isn't slowing down as much on inclines. Time will tell if the mileage comes back.

The old sensor was bare ceramic, while the new one (Bosch) has a metal shroud. Did the shroud break off the stock sensor?

If I disconnect the battery for a few hours, will this "reset" the computer, or is this a myth?

[Bnine]

Disconnecting the positive bat lead, and touching it to the neg for about 10 seconds should reflash everything. Thats  a complete reflash. Dont mix em up

Just disconnecting is called a soft reset or something like that.

But to answer you question, yes, it should do a minor reset by disco'n the bat for a bit.

[redbull]

Pleased to report I got an extra 100km out of that tank!

[Gearhead]

Disconnecting the positive bat lead, and touching it to the neg for about 10 seconds should reflash everything. Thats  a complete reflash. Dont mix em up

Just disconnecting is called a soft reset or something like that.

But to answer you question, yes, it should do a minor reset by disco'n the bat for a bit.

Huh ?

[Mark_93YJ]

Interesting ...

How many miles are on your jeep?  YJ right?

Thus far, I get 450KMs on a tank (72L?) around town in warmer weather.  It seems pretty good.  When it is cold out it drops.

How many KM's are you getting?

What sort of tires?

Mark.

[redbull]

Interesting ...

How many miles are on your jeep?  YJ right?

Somewhere over 260,000 now on the 4.0L, 1991 YJ.

Thus far, I get 450KMs on a tank (72L?) around town in warmer weather.  It seems pretty good.  When it is cold out it drops.

How many KM's are you getting?

What sort of tires?

Mark.  

When I got the Jeep I was getting 600+kms on rock hard 28"s and no lift. Maybe I should also mention MSD coil and plugs, Mopar cap and rotor, new plugs every 6 months and a Poweraid spacer is on there too. After a 2.5" lift and TRXUS 31"s I was getting 450-500kms to a tank. This is still on 3.07 gears.

Then after a trip up to Red Deer, I lost a ton of power and started getting 350-400kms to a tank. Turned out the cat crap the bed, which was probably caused by a rich condition, due to the bad O2.

So far, I'm back up to the 450km area, but it's hard to tell exactly with all the warming up idling in this cold snap. I wouldn't doubt it if I can get over 500 on the hiway again. I really notice that the motor isn't bogging like it was anymore.