jackbombay Posted January 19, 2009 Share Posted January 19, 2009 Hello! I'm new to the board here and have found some good information, but still have a couple of questions that I'm hoping someone knows the answer too. Lately MPGs have been down quite a bit, around town here I got 21 MPG last tank 29 on the highway. we've had the car since 95' and it has never really gotten less than 28 MPG, mid 30s on the highway. The car has a fairly new O2 sensor, the coolant temp sensor seems fine (it starts fine in the cold (well below zero F), according to the subaru mechanic here when the temp sensor fails the car will have cold start issues.) I can certainly check the resistance of it too to make sure its ok. I found a link to the factory service manual in this post which I downloaded. I see that there are 3 ways to check codes, the best/most informative being the "read memory", how do I engage that? I recall something about connecting a couple of wires/plugs under the hood, is that right? Or is that just for the U-check that doesn't provide as much info? The CEL, fwiw, only comes on when running at close to WOT for longer periods of time, like up hills on the interstate, I NEVER see it around town or on the highway at less than 70 MPH. I have a hunch that the MAF is going south, and the manual I downloaded had a good step by step to check it which I will do when I check the coolant temp sensor. Any advice would be appreciated Thanks! Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 20, 2009 Share Posted January 20, 2009 Do you get any codes just reading the LED? Just turn on the key to run, look at the ECU under the steering wheel. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 20, 2009 Author Share Posted January 20, 2009 It blinks 6 times, pauses then 6 more, pauses then six more, etc... The manual I downloaded only has trouble codes for the O2 light blinking Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 20, 2009 Share Posted January 20, 2009 Are the blinks all the same length? Normally, there are some long, then some short. 6 or 66 is not a trouble code. There is a "no trouble" code, I don't remeber if it was 6 or 7 blinks. I didn't find mention of that in the service manual when I was looking for your 6 / 66. But I know it is mentioned in there somewhere. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 20, 2009 Author Share Posted January 20, 2009 Thanks for taking a look for the 6/66 code! All 6 blinks are the same length :-/ I did find a thread about the "test mode connector" , went and plugged it together (the clearish plastic connector under the hood against the corner of the firewall on the drivers side) and I got 2 codes, 32 and 14, according tot he manual I downloaded, that is, "Abnormal O2 sensor signal" and "Abnormal fuel injector output". Now I have some more stuff to search about. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 20, 2009 Author Share Posted January 20, 2009 The local soob mechanic is going to loan me a complete throttle body with injector so I can swap it out with my likely bad one and see what happens. HE didn't have the gasket in stock so I will have to wait till tomorrow to swap it. He said the SPFI injectors rarely go bad so leaving the used one on if it fixes the problem would be fine. Quote Link to comment Share on other sites More sharing options...
Skip Posted January 20, 2009 Share Posted January 20, 2009 did you use an OEM 02 sensor? Maybe check the 02 sensor plug. BTW the light you looked at is called the 02 monitor light With the running and warmed up, at idle you should see it flash in a random pattern. This indicates that the 02 sensor and the ECU are working together. For the cost (~ 20 bucks NAPA for a Bosch) a new one might be in order. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 20, 2009 Author Share Posted January 20, 2009 did you use an OEM 02 sensor? No Its a Borg Warner . With the running and warmed up, at idle you should see it flash in a random pattern. I drove 4 miles and the light was just on steady, but when I got home (after 4 more miles of driving) the light was blinking randomly. It is ~30* F here the car wasn't quite fully warmed up after the first 4 miles of driving. I also hooked up my voltmeter to the O2 sensor, the voltage fluctuated as typical between .1 and .9 I drove about 1/4 mile before the voltage started behving like that/as it should. This indicates that the 02 sensor and the ECU are working together. Thats good, I'll erase the codes (just plug the green connectors together while the engine is running?) and see if the O2 code comes back. For the cost (~ 20 bucks NAPA for a Bosch) a new one might be in order. Hmm, pretty cheap, but as the current one seems ok I'll swap the injector/throttle body first and see how it does. Thanks for the info on the light/Os sensor! Quote Link to comment Share on other sites More sharing options...
Skip Posted January 21, 2009 Share Posted January 21, 2009 that is not the way I use to clear the ECU stored codes. Read here for more http://www.troublecodes.net/Subaru/ From that site: Codes will only clear when the faulty system or circuit has been repaired. After making the repairs, codes can be cleared by connecting 2 pairs of connectors, the "Self-diagnostic" connectors and the "Read Memory" connectors that are usually to the right of the diagnostic connectors. Start with a warmed up engine Turn off the engine Connect both pairs of connectors Fianlly start the engine This should clear the codes. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 21, 2009 Author Share Posted January 21, 2009 Cool, thanks for the link Quote Link to comment Share on other sites More sharing options...
Frank B Posted January 21, 2009 Share Posted January 21, 2009 I've used Borg Warner with good results before, actually I've had an intermittent miss until I replaced a new bosch with a new borg warner! How's your fuel and air filters? Your injector may need cleaning as well. Have you cleaned the MAF? Get some electrical parts/contact cleaner or some brake parts cleaner, they both clean without leaving a residue behind. Remove the MAF and spray the wire. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 21, 2009 Author Share Posted January 21, 2009 I've never cleaned the MAF, Ill do that, cheap and quick. Fuel and air filters are almost at 30k miles, I typically change air/fuel filters cap and rotor and spark plugs at 40k mile intervals. Quote Link to comment Share on other sites More sharing options...
Frank B Posted January 21, 2009 Share Posted January 21, 2009 I've never cleaned the MAF, Ill do that, cheap and quick. Fuel and air filters are almost at 30k miles, I typically change air/fuel filters cap and rotor and spark plugs at 40k mile intervals. The ignition components should be monitored to determine when to replace them, cracks in the wires, worn electrodes on plugs, deposits on cap and rotor, so your intervals may be just fine for those, but unless your in a fairly dust free environment, your air filter should be replaced more often. The fuel filter should be around 15k, but most people only change it when it's clogged. I like to blow through the fuel filter in the direction of fuel flow after the fuel has drained out, then blow through the new one to compare. Quote Link to comment Share on other sites More sharing options...
jackbombay Posted January 21, 2009 Author Share Posted January 21, 2009 This spring I plan on a big service, brake fluid flush, belts, trans oil, rear end oil, coolant flush, and air/fuel filters, glue the door seals back on too LOL Quote Link to comment Share on other sites More sharing options...
jackbombay Posted February 4, 2009 Author Share Posted February 4, 2009 Replacement throttle body is in. Car runs smoother, and notably more power at low RPM and or low throttle settings, also it had an odd hesitation before that is gone. I also cleaned the MAF off with brake cleaner. And I cleared the codes, I'll check in a few days to see if either/both of them come back. Thanks for the help guys! Quote Link to comment Share on other sites More sharing options...
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