only getting 15 miles per gallon on 04 track

[reggis]

Is that normal but I think it used to get around 20 miles per gallon. Just had new plugs and plug wires installed. Do I need to replace anything else?

 

[FR-425]

Originally sold with a EPA rating of 16 city 20 HWY.

Your spot on with that lead foot!

 

[KajunBndit]

I get about 16 in the city and 21 to 23 on the highway.

 

[SoCal2V]

I average about 17-19, and that's with the 4.10 ratio and I'm not very conservative with my right foot.

Things worth trying since you already did plugs and wires would be new fuel filter and clean the MAF (they make an aerosol spray for this very purpose, absolutely do not use anything else).

Just for ***** n' giggles I recently used Seafoam in the gas tank and through the intake via one of the vacuum ports - 1.5 cans in the tank and the remaining .5 can through the intake. With no other changes (including driving habits and commute) my fuel economy came up by 1 mpg (have had two tanks now of solid 19 mpg, where before I've never seen anything better than about 18.2 and it usually hangs around 17). Not trying to be another one of those "Seafoam success story" guys, but if you're bored and feel like buying a couple cans then it's worth a shot.

 

[koda2000]

If you have over 100k it could be your O2 sensors need to be replaced. They're supposed to be good for 120K or so. Is the inside of our tailpipe black and sooty? Do you have a CEL on? Worn out O2 sensors don't always set the CEL. Fuel economy has a lot with differential gear ratio, where and how you drive.

 

[KajunBndit]

Doesn't Seafoam make a lot of smoke comes out of the exhaust? LoLoL I would try that if it wouldn't do that. RAOTF!

 

[SoCal2V]

Doesn't Seafoam make a lot of smoke comes out of the exhaust? LoLoL I would try that if it wouldn't do that. RAOTF!

It didn't when I did it. Maybe I did something wrong (or right, lol)?

I'm not the biggest proponent of Seafoming the intake, as done incorrectly you can really screw something up such as hydrolock your engine. And on a vehicle that's reasonably well maintained, quality fuel used etc there really shouldn't be much to clean besides the typical PCV generated oil residue. The Seafoam "claim to fame" as I understand it is that added through the intake it will clean gum/varnish etc from the intake valves. Which if you run decent fuel and the occasional fuel system cleaner shouldn't be an issue anyway.

 

[KajunBndit]

Thank you SoCal2V.

 

[reggis]

If you have over 100k it could be your O2 sensors need to be replaced. They're supposed to be good for 120K or so. Is the inside of our tailpipe black and sooty? Do you have a CEL on? Worn out O2 sensors don't always set the CEL. Fuel economy has a lot with differential gear ratio, where and how you drive.

I will change 02 sensors to see if that helps. I don't know what the CEL is that your talking about. My tailpipes are black

 

[koda2000]

I will change 02 sensors to see if that helps. I don't know what the CEL is that your talking about. My tailpipes are black

CEL stands for Check Engine Light. It is turned on when the PCM sees an emissions sensor is out of range. Bad O2 sensors don't necessarily turn on the CEL. If your tail pipe is black and sooty, your fuel trims are off, which will occur when your O2 sensors aren't working correctly. At around 110k-120k they're do yo be replaced.

Another thing that can make you run rich is a bad thermostat or bad coolant temp sensor.

 

[Carpin]

I have a 2001 ST, I just hit 120K miles and I want to replace the O2 sensors two, do you know where I can get instructions to do it?

Thanks

 

[SoCal2V]

I have a 2001 ST, I just hit 120K miles and I want to replace the O2 sensors two, do you know where I can get instructions to do it?

Thanks

Just look under the truck, they are located on the midpipe just rearward of the exhaust manifolds. No special tools needed, you can use a regular adjustable crescent wrench but if you want to buy an O2 sensor wrench or O2 sensor socket (yes, there is a specialty tool for this) it is slightly helpful.

There's not much to know. Disconnect battery (more on this later). Unclip the O2 sensor's from their harness on the truck. Using the wrench of your choice, turn the sensor counter clockwise to remove.

Put a little bit of anti-sieze lubricant on the threads of the new sensors, installation is the reverse of removal. No real torque spec that I'm aware of, just snug them down real good. Reconnect the battery.

Battery is disconnected as to erase the pcm's KAM (Keep Alive Memory). Think of it as your vehicle's short-term memory, where things like idle, air/fuel mixture etc values are stored. When replacing a part such as an O2 sensor, disconnecting the battery will allow the pcm to more quickly re-learn those values and make adjustments as necessary.

 

[koda2000]

Just look under the truck, they are located on the midpipe just rearward of the exhaust manifolds. No special tools needed, you can use a regular adjustable crescent wrench but if you want to buy an O2 sensor wrench or O2 sensor socket (yes, there is a specialty tool for this) it is slightly helpful.

There's not much to know. Disconnect battery (more on this later). Unclip the O2 sensor's from their harness on the truck. Using the wrench of your choice, turn the sensor counter clockwise to remove.

Put a little bit of anti-sieze lubricant on the threads of the new sensors, installation is the reverse of removal. No real torque spec that I'm aware of, just snug them down real good. Reconnect the battery.

Battery is disconnected as to erase the pcm's KAM (Keep Alive Memory). Think of it as your vehicle's short-term memory, where things like idle, air/fuel mixture etc values are stored. When replacing a part such as an O2 sensor, disconnecting the battery will allow the pcm to more quickly re-learn those values and make adjustments as necessary.

Don't you mean counterclockwise? Lefty-loosey, right-tighty. Every new O2 sensor I've ever seen comes with anti-seize on the threads.

 

[SoCal2V]

Don't you mean counterclockwise? Lefty-loosey, right-tighty. Every new O2 sensor I've ever seen comes with anti-seize on the threads.

Yup, I stated counter clockwise. You may have missed that - my reading comprehension fails me occasionally as well

And having just recently purchased my first ever set of O2 sensors for a different vehicle, you are correct in that they do already have anti-sieze on them (at least the NGK's I got did). I was speaking more from the experience of re-installing them; one of my other vehicles has had the midpipe on and off a few times.

 

[koda2000]

Yup, I stated counter clockwise. You may have missed that - my reading comprehension fails me occasionally as well

And having just recently purchased my first ever set of O2 sensors for a different vehicle, you are correct in that they do already have anti-sieze on them (at least the NGK's I got did). I was speaking more from the experience of re-installing them; one of my other vehicles has had the midpipe on and off a few times.

Yes, I did miss the "counter". Sorry. just didn't want the OP to be turning them the wrong way a maybe breaking one off. I think you making it 2 words may have also thrown me off. Plus I'm going for a cathartic evaluation tomorrow morning. The old eye sight just isn't what it used to be. Sucks to get old.

 

[SoCal2V]

No worries Koda.

 

[429CJ-3X2]

Yesterday we made a 237 mile round trip from Des Moines to Iowa City and back in my 2002 ST, 3.73 gears, topper plus maybe 100 - 150 lbs of tools & junk in the back, about 500 lbs of passengers. On the way over we had a nice tailwind from the NW. By the time we started back the wind, now a head/cross wind, had picked up tremendously, and was gusting up to 62 mph most of the way home. Gusts were "only" 48 mph in Des Moines. As long as I stayed over 70 mph I could maintain a steady speed. Anything under 70, it would slow too much on the hills and take more gas to keep the pace. The ST handled it pretty well and got 17.3 mpg for the trip. That was on 10% ethanol. On a calm day, I would have expected about 19 mpg. I don't think 17.3 was too bad for the conditions.

 

[Carpin]

I want to buy the O2 sensor and fuel filter, do you know the part numbers? also if you recommend a specific brand for them

My truck is a 2001 Sportrac 4X4 4.0 Manufacturing date 08/01

 

[koda2000]

I want to buy the O2 sensor and fuel filter, do you know the part numbers? also if you recommend a specific brand for them

My truck is a 2001 Sportrac 4X4 4.0 Manufacturing date 08/01

Re the fuel filter: Check to see which fuel filter you have. The late '01's sometimes came with a 3-port fuel filter. Mine did. If so, the only store that had it in stock was O'Reilly's and it was rather expensive at around $20. Having the extra rear port also made it that much harder to change, which isn't an easy job to begin with.