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Replacing O2 sensors for improved mileage?

1K views 5 replies 4 participants last post by  Leeann_93 
#1 ·
I am trying to keep myself in check from just throwing parts at my "new" van. I read somewhere, on here I think, that old O2 sensors get lazy and mess with fuel mileage. Mine do look like the switch a bit slow
What's your opinion? Are all 3 O2 sensors the same part? I was thinking of swapping the front 2 with new Denso #2344646
Thanks
 
#2 ·
No, the three are not all the same, usually there will be a heated sensor, which means

it has an element in it so that it will come up to working temperature b/c of its' position

so far down the pipe from the exhaust (heat source). Denso seems to be the brand that

most of the guys and gals here prefer. I would consider a replacement if you think or

know that any/all have more than 150k mi on them. Let the counter guy/gal give you

what the computer says is the right parts. Number of wires in the connector will tell

you where they should go.

Uncle Bob
 
#3 ·
Cool, thanks for the fast reply. I am at 140k, just got the van without full service records. Though there were some. SO I am going to do all 3 in prep for our road trip up to Canada! I usually buy parts online if I can figure out exactly what I need. I will take a look at the sensors before replacing. If there are heates sensors I would guess that's the front 2. Thanks for the help
 
#5 ·
Yeah I went back and took a look at it, and decided the readings weren't horribly sluggish, so I am not droppin $100 to replace them all right now. They all look the same though, 4 wire type
I think if it was your post CAT o2 sensor, that would definitely not affect mileage because it only monitors the effectiveness of the CAT, if I understood your comment correctly.
I average just over 17mpg mixed driving right now. I am not too worried about my mileage I think, it's just that I am giving the van an overall going-through and anything that will get it closer to new running condition I will do.
 
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