I can't break 26mpg

[Matt Timion]

Originally Posted by SVOboy

Hell, just pull the o2 and look at it and see if it looks like crap. 60 bucks ain't really terrible for an o2, of course my car will take a 17 dollar o2, but it's a piece of crap, I'd gladly pay 60 to get the one I wish I was running, :-), might be worth trying swapping them, mehbe your cat is bad or junked up? You can always pull an 02 from the junkyard and swap it and see if there's a difference.

The cheapest I can find my o2 is $180. Honda sells them for over $300.

Anyway, SVOBoy makes a good point about the CAT. I had a 2000 V6 Jeep Wrangler that I drove for a little over a year. It was horrible going up hills (I'm speaking of Parley's Summit near Park City, UT). I can understand a 4 cylinder having problems with that route, but not a v6 Jeep.

Then my friend told me that his friend's jeep did the exact same thing. It turned out that the CAT/exhaust was clogged. It was creating extra back pressure and bogging the engine down.

i'd check the CAT personally.

[Compaq888]

It goes rich not because of the o2 sensor but because of the ECU. It's common on nissans. NGK coppers actually improved my mileage because platinum is made for longer life.

I have never got my mileage this high under platinum plugs. I got the same 28.7mpg but that was all freeway. This 28.7mpg that I got yesterday was 60% freeway and 40% city. So the mileage increased.

The only difference I made was switching to copper plugs and switching to royal purple. So they work for me.

[SVOboy]

Try gapping/modifying your plugs, see if that helps. You could always get a piggy back sensor to keep the ecu from maxing out fuel injection.

[Compaq888]

I got some more stuff in my mind that can increase fuel economy. The ecu only starts going rich around 3000rpm. On the streets i'm below 2000 and on the freeway below 2500rpm.