Horrible MPG. HELP
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Newbie
Joined: May 2016
Posts: 8
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O I6
Horrible MPG. HELP
I have a 1992 cherokee XJ with a 4.0 H.O, automatic transmission. It gets horrible gas mileage (9mpg). I've seen a bunch of things about o2 sensors. I only have one. And it is after the manifold, and before the cat. I unplugged it from harness to see how it would run and it doesn't run any different. I'm not exactly sure what is wrong. Help would be greatly appreciated! -Bryce
1992 XJ
4.0 h.o
4.5 inch lift
33 inch tires.
180xxx miles
1992 XJ
4.0 h.o
4.5 inch lift
33 inch tires.
180xxx miles
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Joined: May 2016
Posts: 16
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Model: Cherokee
My suggestion is to replace the O2 sensor. If you unplugged it and it made zero difference, that leads me to believe that it has probably failed. If you don't know when it was replaced last, it's due anyway. They are a consumable maintenance item.
Thread Starter
Newbie
Joined: May 2016
Posts: 8
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O I6
That's what I was thinking but I would hate to waste money on the sensor. Money is tight. Is there a way I can check if the sensor is bad without having to buy a new sensor?
Thread Starter
Newbie
Joined: May 2016
Posts: 8
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O I6
Ignore my last message lol don't know how to delete it.
That's what I was thinking but I would hate to waste money on the sensor. Money is tight. Is there a way I can check if the sensor is bad without having to buy a new sensor?
CF Veteran
Joined: Dec 2015
Posts: 2,139
Likes: 93
From: Syracuse, NY
Year: 1996
Model: Cherokee (XJ)
Engine: 4.0L
The oxygen sensor is very important to the fuel usage in your engine. It is what gives your engine computer the data it needs to adjust fuel trim levels. If it is not working, it can most definitely lead to terrible gas mileage (and a variety of other annoyances). Without data coming from the sensor (in the form of various voltage readings) the engine will use "fake" values in order to keep the system going, but these values are not efficient or powerful.
Google "how to test an oxygen sensor"
Google "how to test an oxygen sensor"
Member
Joined: Feb 2016
Posts: 211
Likes: 2
From: Tucson, AZ
Year: 1999
Model: Cherokee
Engine: 4.0L
I have a 1992 cherokee XJ with a 4.0 H.O, automatic transmission. It gets horrible gas mileage (9mpg). I've seen a bunch of things about o2 sensors. I only have one. And it is after the manifold, and before the cat. I unplugged it from harness to see how it would run and it doesn't run any different. I'm not exactly sure what is wrong. Help would be greatly appreciated! -Bryce
1992 XJ
4.0 h.o
4.5 inch lift
33 inch tires.
180xxx miles
1992 XJ
4.0 h.o
4.5 inch lift
33 inch tires.
180xxx miles
Have you recalibrated the speedometer?
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Thread Starter
Newbie
Joined: May 2016
Posts: 8
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O I6
Thread Starter
Newbie
Joined: May 2016
Posts: 8
Likes: 0
Year: 1992
Model: Cherokee
Engine: 4.0L H.O I6
CF Veteran
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Posts: 8,567
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From: ☼ Blackhole Sun
Year: My Jeep is a GMC
Without accurate information this thread is rather pointless...
Try this:
First calibrate the speedometer:
http://www.quadratec.com/jeep_knowle...article-46.htm
Then,
Fill the gas tank, drive til almost empty and refill the gas tank, note the miles driven and gallons consumed. Do this 6 times, then for each tank of fuel calculate: miles driven/gallons used. Take these 6 figures add them up then divide that number by 6, this will give you a rough estimate of miles per gallon.
Try this:
First calibrate the speedometer:
http://www.quadratec.com/jeep_knowle...article-46.htm
Then,
Fill the gas tank, drive til almost empty and refill the gas tank, note the miles driven and gallons consumed. Do this 6 times, then for each tank of fuel calculate: miles driven/gallons used. Take these 6 figures add them up then divide that number by 6, this will give you a rough estimate of miles per gallon.
Thread Starter
Newbie
Joined: May 2016
Posts: 8
Likes: 0
Year: 1992
Model: Cherokee
Engine: 4.0L H.O I6
Without accurate information this thread is rather pointless...
Try this:
First calibrate the speedometer:
http://www.quadratec.com/jeep_knowle...article-46.htm
Then,
Fill the gas tank, drive til almost empty and refill the gas tank, note the miles driven and gallons consumed. Do this 6 times, then for each tank of fuel calculate: miles driven/gallons used. Take these 6 figures add them up then divide that number by 6, this will give you a rough estimate of miles per gallon.
Try this:
First calibrate the speedometer:
http://www.quadratec.com/jeep_knowle...article-46.htm
Then,
Fill the gas tank, drive til almost empty and refill the gas tank, note the miles driven and gallons consumed. Do this 6 times, then for each tank of fuel calculate: miles driven/gallons used. Take these 6 figures add them up then divide that number by 6, this will give you a rough estimate of miles per gallon.
It says these are for a 93-04 models. Where can I find one for a 1992?