I have lost 2-3 mpg on my 1993 2 wheel drive Sidekick. I obtained the diagnostic code from the ECM following the Haynes manual but it showed a normal code. I checked the O2 sensor with a millivolt meter but I'm not sure that the result was conclusive. Any help or direction would be appreciated.
I have lost 2-3 mpg on my 1993 2 wheel drive Sidekick. I obtained the diagnostic code from the ECM following the Haynes manual but it showed a normal code. I checked the O2 sensor with a millivolt meter but I'm not sure that the result was conclusive. Any help or direction would be appreciated.
2mpg is nothing....
just a minor driving, change.
19 to 30 is the spec range, i can do any , of those on demand.
so can you, so can anyone. as the say, YMMV !
are ohbummer says, pump up dem tyres.
get the scan tool, and stop guessing if ecu is happy.
Normally, the o2 sensor slowly begins to fail after 100,000 miles - and its replacement is part of the 100,000 mile check. When it begins to fail, it causes the car to run richer, as a safety precaution.
Normally, however, 2-3mpg might depend on your driving, use of winter fuel or ethanol, etc. at the gas station, if you are doing anything in 4wd, etc.
If you are getting code 12 from the ECU, it means that the ECU does not see any 'gross' errors, however, the ECU doesn't see if your car is tuned up properly, if your spark plugs are in good condition and gapped properly (gap at .028"), if your fuel pressure is good, or if your car is heating up properly, etc. You can pull the plugs and see by the tips if there is an indication of the car running rich. But, aside from gas mileage, you don't advise whether the car is running well, if there is any bogging or hesitating, if the hot idle is at 800 rpm, if the car is heating up to proper running temp, etc. If any of these things are happening, you may want to post for more info.
Sorry-more info. We have had this 1993 4 door Sidekick for about 11 years. Great car. It is the 2 wheel drive version, 5 speed with 220000 miles. I check the gas mileage every so often just to see how it's doing. For my normal driving it has always obtained 28mpg regardless of the weather. I checked it recently and noticed I'm only getting 25-26mpg. No change in my driving, the car runs fine. Idles normal, the engine heats up properly. No running problems at all that I can tell. I didn't think about checking the plugs to see what color they are, I will do that. When I checked the ECU the code was 12. Is there an accurate way to check the O2 sensor?
If you have never changed the o2 in 11 years with 220,000 miles, then it certainly is time to do it. You also don't advise what maintenance you have done - recent tune up? Change and gap spark plugs and wires? Replaced air filter? Car is idling at 800 rpm steady (so no vacuum leaks)?? All of these things will affect mileage.
the ecu will not report, 2mpg low. not ever. (LOL) (but if not in closed loop at idle, it will suck fuel at idle. or at cruise, and the scan tool shows you that fact...)
and not putting in 02 sensor at 80-100kmiles, invites this...
why not do the 60k tune up and the 80k (8v 02s are changed, sooner , a more dirty motor)
buy a scan tool, after the 02 is new, and the mph is low.
see if hit holds closed loop at all times , it must, idle and cruise.
these old year cars dont report a dead heater in the 02, ( it just pops open, not slowly , the heater just burns out, like a flash bulb,, the CELL side, 02 side, does get poisoned in time.)
use an ampclam amp meter see if o2 draws 1amp, key on..
most don't. due to lack of maintenance. (at 80k _miles on 02)
the 02 heater is short lived.... in terms of 200k. on any clock.
that is correct, i to monitor mpg , for only that same reason. something, is up.? (get a scan tool , it will pay for itself, in labor, fuel, and parts thrown wrong)
see first link in my page to old 0bd1 cars here... http://www.fixkick.com/ECU/Authority...OBD2_scan.html
but not in the city, city mpg varies with , well , traffic. (snow, ice,speed, idling times., frustration, hot right foot, etc, YMMV, IIRC. LOL)
you glove box missing the op guide. its free. to all drivers (60,120,180,240.. and so forth)
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