Probably not going to have effected your mileage if it's been like this for a while but whenever I reset my ECU I usually get a crap tank following up.

 

both of our tanks are 15.9 gallons or 60L and yes i did reset the ecu!!!

 

i did use injector cleaner and my car has 120 000 miles about!

 

When was the last time you changed the spark plug wires? If you checked the spark plug you obviously unhooked the wires. They seem to get damaged easy when removed, and they could be just plain old. That would def. cause the problems you see, expecially since you did remove the wires and put them back on and seen a performance decrease.

 

Was this the first tank after you did the reset? The reset clears the trip meter and if you dont have a full tank it messes up the mileage. Ive done it before. :lol:

 

would the wires really make that much of a difference in the economy??
and i dont remember if i did full fill ups since the reset.
i do know that the plugs are relular copper or whatever. im thinking of getting the ngk iradium ix onse.

 

Yea, spark plug wires increase in resistance over time, that increase in resistance causes weak spark, as well as sometimes the spark will escape the wire and basically spark out of the wire instead of the spark plug.

 

Does your car idle funny sometimes, like it suddenly "hiccups" at random? Back when I was in HS and driving a 93 leggy, I thought the same thing, there just wires, i had the same problem, my gas milage was getting worse and worse, eventually the car started hiccuping (missing) at idle. My dad had a good laugh to see how long I delt with it and did nothing on such a simple thing. When it was fixed I couldnt belive how much power my car had.

 

u know sometimes it does! but i thought its because of the maf! cause i have an intake and the filter was coved by blowing snow. so i dried it and put a cardboard and it seemed to go away.
thats why i didnt assume the wires.
your problem was that it was letting the humidity in the wire and short circuiting the spark.

 

Plug wires are very important. If they haven't been changed in the time you have had car change em wether or not they look good/bad.

They can get internally damaged and the performance would be the only sign, and if you totally ignore the performance change then your losing out. Kinda hard to test plug wires, but if you do have a dvom / dmm test resistance. Base ohms is 10k ohms per foot, but not exceeding 30k ohms per wire. Even tho resistance isn't the best way to test most things.

Also too see if your getting a short to ground start up car then get some water and spray it on wires and see if it hickups.

 

ya thanks i measure their resistance. but with the water spray test they are good.
i just now thinking if i should change the o2 sensor, but i dont want to waste money for nothing! and mine isnt giving me any codes

 

Reseting your ecu means it has to learn everything again, as someone said before. Im not sure why you did it in the first place, since it would of pry learned around anything you did.

 

when i did do the reset for the first tim after owning the car for a few months it did improve to my driving habits but im saying it didnt do too much.
im thinking im going to buy new plugs and wires and hopefully i see a difference because i just have nothing else to do!

whats plugs are better for subarus? NGK LASER PLATINUM OR NGK IRADIUN IX?

 

Bump any updates? My car is having horrible gas mileage and is driving sluggishly :/

 

What have you done or not done to fix

Sent from an other planet (Tapatalk)

 

Bump

 

Try sending a PM instead of resurrecting a 7yr old thread. :unamused:

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Thanks for helping