jcniest5 Posted October 7, 2007 Author Share Posted October 7, 2007 are you basing your conclusion of 'running crappy' on the movement of the gas gauge or on your MPG from gallons pruchased and miles driven. if you are using just the gauge, these guages are known for reading wrong (low). it could be mis leading you. if on the other hand you are actually dividing miles driven by gallons purchsed, it may take a a little while to show your actual mileage. how many miles are you driving it on your test drives, 5 - 10 or 100 - 150?? more miles will give you a better idea of what is actually happening. Well, it has never done this before until very recently, so I determine it by comparing to how fast the gauge moves now vs. in the past. Also, a full tank of gas used to last 300+ miles. Now, it's like around 200. That tells me something is really wrong with the car. Quote Link to comment Share on other sites More sharing options...
Cougar Posted October 8, 2007 Share Posted October 8, 2007 The sensor for the ECU usually has two wires going to it, instead of one that is for the gauge. It may be located behind the throttle body on the passenger side of the engine. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 8, 2007 Author Share Posted October 8, 2007 Okay, by reading the tech manual, I was able to unscrew out the sensor. I'm measuring its ohms according to the manual, but since I don't have a thermometer, I can't tell how hot or how cold the water I'm putting the sensor into. Just to isolate the problem, I think I'm just gonna replace it and see if it would make any difference. Update: I put it right next (actually stick it into) my AC's vent, which suppose to be around 65F and it's suppose to have a resistence of around 3 Ohms. It stays at 2.4 Ohms, so I'm assuming it's off by at least .6 Ohm. I just hope this is the culprit as poor man is running out of $$ to troubleshoot this car further. Quote Link to comment Share on other sites More sharing options...
ericem Posted October 8, 2007 Share Posted October 8, 2007 Actually should be around 40-50F. Did you check out the fuel filter? Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 8, 2007 Author Share Posted October 8, 2007 I don't know the real/correct temperature by the AC's vent, but the ohms manage to reach 3.00 and going up. Just so confusing right now. Quote Link to comment Share on other sites More sharing options...
ericem Posted October 8, 2007 Share Posted October 8, 2007 I don't know the real/correct temperature by the AC's vent, but the ohms manage to reach 3.00 and going up. Just so confusing right now. Tell me exactly what you have replaced so far? Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 8, 2007 Author Share Posted October 8, 2007 Tell me exactly what you have replaced so far? So far, the only item I've replaced is the Speedometer gauge. No sensor of any kind has been replaced yet. The one I will do tomorrow is the Engine Coolant Temperature Sensor. Not even sure if the store I called has it or just the regular Coolant Temperature Sensor for the gauge (and not for the computer-ECU). Quote Link to comment Share on other sites More sharing options...
ericem Posted October 8, 2007 Share Posted October 8, 2007 I suggest you try replacing the fuel filter and/or plugs and wires. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 8, 2007 Author Share Posted October 8, 2007 I suggest you try replacing the fuel filter and/or plugs and wires. Both the wires, plugs and fuel filters were replaced back in '05. Wouldn't think they need replacing this soon, do they? Quote Link to comment Share on other sites More sharing options...
ericem Posted October 8, 2007 Share Posted October 8, 2007 Well you said this happened all of a sudden anything is possible. Could have been bad fuel. is the car driving any different? meaning more rough and slower? So many different possible things, even just a bad tank of gas. Quote Link to comment Share on other sites More sharing options...
Cougar Posted October 8, 2007 Share Posted October 8, 2007 To check the sensor resistance you can place it in a shallow pan of near boiling water. You know that it will be close to 212 deg F. Then check the resistance of the sensor when it has heated up to the water temperature. Compare what the reading is to the chart and see if it is close. I would guess that it should be within about 5 to 10 ohms of the chart if it is ok. Can you tell me what the chart says the resistance should be when the temperature is around 195 degress? Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted October 8, 2007 Share Posted October 8, 2007 Well, it has never done this before until very recently, so I determine it by comparing to how fast the gauge moves now vs. in the past. Also, a full tank of gas used to last 300+ miles. Now, it's like around 200. That tells me something is really wrong with the car. this is fairly typical for these fuel gauges. i have 2 that read empty after 200 miles, but when i fill them up they onlt take around 8 - 10 gals. try some techron fuel additive. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 8, 2007 Author Share Posted October 8, 2007 Okay, I just replaced the CTS. Will drive to work (20 miles each way) and see how it goes. Will report back after work tonight. Thanks, guys! Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 9, 2007 Author Share Posted October 9, 2007 Well, unfortunately, my gas gauge still moves as fast, so I think it's not the CTS. Not sure what to try next now. Should I try the Oxygen sensor or should I try plugs and wires? Quote Link to comment Share on other sites More sharing options...
ericem Posted October 9, 2007 Share Posted October 9, 2007 Plugs and wires no doubt. Alot cheaper as well. Go OEM for the wires and for the plugs go with NGK v powers. g powers suck lol i have compared doesn't take much to kill the g power plugs and i lost performance with g powers. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 9, 2007 Author Share Posted October 9, 2007 Is NGK's Iridium sparkplugs good? I think that's what I have right now, but I don't remember if it improve or decrease my MPG. I put them on back in '05, I believe. The wires, I went with Checkers Auto or some similar store's brand. I will call Subaru for the price tomorrow. Thanks again, guys. Quote Link to comment Share on other sites More sharing options...
ericem Posted October 9, 2007 Share Posted October 9, 2007 Iridiums I beleive are fine although plugs can go every 20-80k miles. Give some V-power coppers ago at a $1 a piece its worth a shot. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 9, 2007 Author Share Posted October 9, 2007 Just a thought. If when I pull out the plugs and they are still good/clean/no carbon build-up and with no odd sign of wear, is replacing them still necessary? I guess I'm trying to save some money, but I truly want to fix this poor gas mileage problem I'm having right now. Quote Link to comment Share on other sites More sharing options...
Cougar Posted October 9, 2007 Share Posted October 9, 2007 I would say if the plugs look good then replacing them and the wires aren't going to help much. Replacing the O2 sensor may be the next best step and then the MAF sensor if that doesn't help. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 9, 2007 Author Share Posted October 9, 2007 I would say if the plugs look good then replacing them and the wires aren't going to help much. Replacing the O2 sensor may be the next best step and then the MAF sensor if that doesn't help. How long does an oxygen sensor usually last? I think I replaced mine back in '04 or '05. I got an aftermarket one instead of an OEM, does that matter? I had to do some wiring as the aftermarket doesn't have the connector, just three wires, so I had to use the old connector/harness. Do you suppose I could done have the wiring wrong somehow? Wouldn't a bad oxygen sensor give out an ECU code (Check Engine light comes on)? Quote Link to comment Share on other sites More sharing options...
Suzam Posted October 9, 2007 Share Posted October 9, 2007 Well, it has never done this before until very recently, so I determine it by comparing to how fast the gauge moves now vs. in the past. Also, a full tank of gas used to last 300+ miles. Now, it's like around 200. That tells me something is really wrong with the car. I read this post over and still haven't seen a conformation of your actual gas milage. The MY95 Legacy I had used to be on "E" by the time I hit 220 miles on the trip odometer. I could bearly fit over 8 gallons into the tank, so I was still getting almost 26 MPG. You can not trust the movment of the needle alone for MPG. Confirm your gas milage by driving say 100 miles and filling the tank so you know for sure. Or at least tell us how many miles for how many gallons of gas you are getting. Quote Link to comment Share on other sites More sharing options...
Manarius Posted October 9, 2007 Share Posted October 9, 2007 I read this post over and still haven't seen a conformation of your actual gas milage. The MY95 Legacy I had used to be on "E" by the time I hit 220 miles on the trip odometer. I could bearly fit over 8 gallons into the tank, so I was still getting almost 26 MPG. You can not trust the movment of the needle alone for MPG. Confirm your gas milage by driving say 100 miles and filling the tank so you know for sure. Or at least tell us how many miles for how many gallons of gas you are getting. Ditto on this. Gas gauges lie. Reset the trip, drive 200 miles, and tell us how many gallons you put in. For all we know, you could be chasing a ghost and getting 20-25mpg anyways. Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 9, 2007 Author Share Posted October 9, 2007 I just put in 12 Gallons of gas in my car yesterday when the needle almost pointed directly at the E, so I know the gauge doesn't lie. I have yet to drive the car in a 100+ miles straight, but my guess is that someway, somehow, the car has been using gas much more than it did before the speedometer cable got pushed out and I was driving the car with Zero speed reading for a week or so. I'm driving out of town tomorrow (close to 200 miles each way) so I would know how it will behave then. My instinct tells me it may not be the plugs or wires, or fuel filter either. I believe if there is problem with these, they would only give my car a sluggish performance (ie: no power when accelerating, no power when climbing hill, etc...) As of right now, my car performs just fine, no sluggish acceleration and it has lots of power to climb any hill. I think it's gotta be one (or some kind) of sensors, something that tells the computer how to properly mix the fuel and air ratio. Oxygen sensor is on my list right now as the next item to replace, but like I said, I just replaced it not too long ago. Should I try it or not? Poor man's pocket is getting lighter. Quote Link to comment Share on other sites More sharing options...
Suzam Posted October 9, 2007 Share Posted October 9, 2007 I just put in 12 Gallons of gas in my car yesterday when the needle almost pointed directly at the E, so I know the gauge doesn't lie. So how many miles did you go on 12 gallons????? Quote Link to comment Share on other sites More sharing options...
jcniest5 Posted October 9, 2007 Author Share Posted October 9, 2007 So how many miles did you go on 12 gallons????? Per 12 gallons tank, around 200 now, used to get 300-350. And I've used different brand gas for the past two weeks or so, so it's not just a bad tank of gas. It's really the car's using more gas now... Quote Link to comment Share on other sites More sharing options...
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