Spaceman Spiff Posted November 1, 2017 Share Posted November 1, 2017 I had no problem driving this car anywhere before the ECU reset, now I can't get it above 25mph. BUT IT STARTS AND IDLES GREAT! Here's the history. I bought this car in March with 103K. It had brake and bearing issues so it sounded like hell going down the road. So I got it for about half price. So I took care of the noises easily and was very happy...for a day. I drove it to work ONE day and about 1 mile from returning to my house the turbine fell off the end of the shaft and was making a tinny bee-buzzing sound. So I parked it and started reading about all the horrors of 2005s and their broken turbos. My turbo had no bearing issues or side-play and the oil looked good. I went and pulled the screen from the banjo bolt anyway. I order a remanufactured turbo from bustedfingermotorsports on ebay and went to work on the install. First I swapped out the OEM uppipe for an Invidia and in the process of reinstalling the turbo the inlet ripped. So i ordered a REV9 inlet and then had to move. So I flat-bedded it to my new place where it sat for 5 months. With the tags about to expire(actually expire today), I got back to work on it and cracked open the IM enough to get the inlet in there. It was actually way easier than it sounded and fit perfectly. I got it all back together and I immediately got a p0171 and boost cut. When I had put it back together, I used a K&M drop-in. OOPS After a short trip to the parts store, I got a paper element and that got rid of the CEL and it ran pretty well, but was stumbling a little on idle and occasionally would be sluggish on acceleration. It was also very hard to start, like it wasn't getting much gas. So after numerous attempts to find leaks or other p0171 causes, I was clearing the codes and I could not get the ECU to happy enough to not have that codes reoccur the second or third time I got up to highway speed. So I'm running lean and was wondering if I NEED to get a tune to make this work. Then I started reading about resetting the ECU. I thought turning off codes "reset" the ECU. So I thought maybe it learned enough from that K&N trip that it screwed it up. So I disconnected the ground from the battery and stepped on the brake for 20-30 seconds, then started and let it idle for 10 minutes. I let it sit for a half hour and it cranked over and idled like new. Finally??? Did I get it? I thought I did. But when I tried to take off, the car was bogging badly and throwing misfires flashes on the CEL. I'm hoping that I finally got everything lined up electronically, and that the fuel pump just crapped out. I have spent the last couple weeks looking for other p0171 causes, but can't come up with any. My front O2 sensor looks pretty new, but idk how long its been on there. It was dangling for 6 months or so. Assuming there are no vac leaks, I'm thinking fuel pump or maybe O2. Again, I've gone down the p0171 list already. I replaced the IM to TGV seals. Is the fuel pressure test the way to go? Thanks. Stephen Again, I had no problem driving this car anywhere before the ECU reset, now I can't get it above 25mph. BUT IT STARTS AND IDLES GREAT! Link to comment Share on other sites More sharing options...
Norskie Posted November 1, 2017 Share Posted November 1, 2017 Could it be as simple as cleaning the MAF sensor? What other codes besides P0171 are you getting? Link to comment Share on other sites More sharing options...
MilesA Posted November 1, 2017 Share Posted November 1, 2017 When you have trouble like this, you should look at what you have done to the car most recently for the likely cause. P0171 indicating a lean condition is a clue. Do you have any other CELs? You said you got misfires? Another clue is that idle is good, but the engine craps out under load. If your O2 sensor was at fault, I would expect that to show up at idle, yet your car is idling fine. P0171 can be related to the intake system, since you had the IM at least partially off and installed a new inlet, I would wonder whether you had all the vacuum lines hooked up correctly and also about the intake manifold gaskets, which are a known weakness for this model year. Another possibility is the fuel system, not enough fuel when the engine is under load. This could be related to the intake manifold vacuum reference used by the fuel pressure regulator. I would check that is all connected properly. You can put a vacuum gauge on the intake manifold and observe the readings. It will give you enough info to rule out a vacuum leak. Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 1, 2017 Author Share Posted November 1, 2017 I get no other codes besides the p0171. I cleaned the MAF. I replaced the IM gaskets. I have clamped and zipped all vac lines. Checked them all twice or more and sprayed around some carb cleaner. It was hard to start and idled poorly (but drove ok) before the ecu reset. And nows it starts and idles correctly, but bogs under load. No other changes were made at the time of resetting. I'm thinking that now that it wants the right amount of gas, the pump can't deliver it. This car has been driven very little in the last 2 years. Like a couple hundred miles. Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 1, 2017 Author Share Posted November 1, 2017 You can put a vacuum gauge on the intake manifold and observe the readings. It will give you enough info to rule out a vacuum leak. Thanks. I'll give that a try. Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 1, 2017 Author Share Posted November 1, 2017 What if my car had a tune on it unbeknownst to me? Would resetting the ECU send it back to OEM? Link to comment Share on other sites More sharing options...
hadvw Posted November 1, 2017 Share Posted November 1, 2017 What if my car had a tune on it unbeknownst to me? Would resetting the ECU send it back to OEM? No, it just resets CEL codes and fuel trim adjustments (i.e. the "learned" parameters), AFAIK. It COULD, in theory, be the case that your ECU had learned a LOT to get around the badness of your setup, and resetting has made it forget that, so it's starting over and will need to re-learn how to function in the current environment. But don't quote me on that Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 2, 2017 Author Share Posted November 2, 2017 [quote name=It COULD' date=' in theory, be the case that your ECU had learned a LOT to get around the badness of your setup, and resetting has made it forget that, so it's starting over and will need to re-learn how to function in the current environment. But don't quote me on that [/quote] Wow, you probably saved me a bunch of time and agony. I started it up again and tried accelerating in park and it was still bogging. So I let it sit and idle while I lightly tapped the gas pedal until it was smooth. Then I took it out on the road(of course, forgetting my tags expired today) and it drove like it should. I'm glad I saw your post right before I headed out to O'Reilly's auto. Many thanks. Now I have to get a trip permit so I can get the computer ready for the smog test. Hopefully I won't see that light again. But it does feel like the lean condition is gone. I hope the ecu agrees. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 2, 2017 Share Posted November 2, 2017 Have you ever checked for vacuum leaks? Link to comment Share on other sites More sharing options...
BoozeRS05 Posted November 3, 2017 Share Posted November 3, 2017 ^ that. I wouldn't assume it'll just fix itself with road time. Not a bad idea to get someone to look over your work. EB's Subaru journal - 2005 LegacyGT Wagon & 2014 Forester FB25 (2008 specB - RIP) IG@legacygtliving Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 3, 2017 Author Share Posted November 3, 2017 I know I'm not out of the woods yet, but I did mention twice already that I checked for vacuum leaks. That's obviously first when you take off your IM and inlet. My goal right now is to pass smog and then the car goes to Cobb Surgeline for stage 2 dynotune. I'm sure they'll smoke it first. For starters: Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 3, 2017 Share Posted November 3, 2017 Time to log. Do you have a way to do this? I use the btssm app. Can't beat its versatility and what it can report. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 3, 2017 Share Posted November 3, 2017 You want to log most of the parameters shown here. Particularly, you want to see that your fuel learn values A through D are very close to zero and not pegged to +/-15%. If pegged or high, you still have a leak somewhere or there is an issue with MAF and/or O2 sensors or possibly use of a non OEM air filter with stock tune. http://legacygt.com/forums/attachment.php?attachmentid=213955&d=1438707135 Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 3, 2017 Author Share Posted November 3, 2017 So that's what logging looks like? Um, I'll cross that bridge when I find it. I'm planning on getting an AP with my tune. They give you $200 off on the dynotune if you get an AP at the same time. For now, I'm just hoping it will pass smog. If it doesn't, then I will probably have to log to get it to pass. Of course, then I might be tempted to etune if I have to invest in a laptop and cables. Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 5, 2017 Author Share Posted November 5, 2017 You want to log most of the parameters shown here. Particularly, you want to see that your fuel learn values A through D are very close to zero and not pegged to +/-15%. If pegged or high, you still have a leak somewhere or there is an issue with MAF and/or O2 sensors or possibly use of a non OEM air filter with stock tune. http://legacygt.com/forums/attachment.php?attachmentid=213955&d=1438707135 Oh OK, I get it now. Thanks. I went out and got a cheap laptop and I'm trying to get the Java on there to satisfy the romraider. Link to comment Share on other sites More sharing options...
BoozeRS05 Posted November 7, 2017 Share Posted November 7, 2017 Btssm is what you see in his pic there. Amazing homebrew vendor here from our forum created and maintains the app, and many of us use it. The apps available on your phone or tablet too - search btssm, $15. http://www.btssm.com The wireless bluetooth odb plug is highly recommended, although specific and $80 EB's Subaru journal - 2005 LegacyGT Wagon & 2014 Forester FB25 (2008 specB - RIP) IG@legacygtliving Link to comment Share on other sites More sharing options...
hadvw Posted November 7, 2017 Share Posted November 7, 2017 The wireless bluetooth odb plug is highly recommended, although specific and $80 I believe the app is $15 and the BTSSM bluetooth dongle is $100? Link to comment Share on other sites More sharing options...
jonnyt88 Posted November 7, 2017 Share Posted November 7, 2017 I have a spare LGT MAF from an 08 or 09, which is good for an OBXT. Hit me up if you think you might need one. You would want to confirm the 05-06 compatibility. I had a 0171 code I was chasing around and I bought a MAF from a Wrecked LGT. while it was on Fedex I decided to clean mine good first, and two full tanks of gas with no more code. Never needed the replacement Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 7, 2017 Author Share Posted November 7, 2017 Btssm is what you see in his pic there. Amazing homebrew vendor here from our forum created and maintains the app, and many of us use it. The apps available on your phone or tablet too - search btssm, $15. http://www.btssm.com The wireless bluetooth odb plug is highly recommended, although specific and $80 Well, thanks for another option. I will explore that as well. First, I'm making a smoke machine. Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 7, 2017 Author Share Posted November 7, 2017 I have a spare LGT MAF from an 08 or 09, which is good for an OBXT. Hit me up if you think you might need one. You would want to confirm the 05-06 compatibility. I had a 0171 code I was chasing around and I bought a MAF from a Wrecked LGT. while it was on Fedex I decided to clean mine good first, and two full tanks of gas with no more code. Never needed the replacement Thanks. I appreciate that. But I do have an 08 LGT as well. I just wished they used the same o2 sensor. Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 7, 2017 Author Share Posted November 7, 2017 What about that connector that's leftover from the sensor that gets deleted(pcv leak detection??) during the inlet install? That just gets jumped, right? Again, can one install an aftermarket inlet and aftermarket catless uppipe at the same time and not NEED a tune? Don't they increase airflow, or is it not enough to matter? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 7, 2017 Share Posted November 7, 2017 You want to log most of the parameters shown here. Particularly, you want to see that your fuel learn values A through D are very close to zero and not pegged to +/-15%. If pegged or high, you still have a leak somewhere or there is an issue with MAF and/or O2 sensors or possibly use of a non OEM air filter with stock tune. As I mentioned above, if you do use an aftermarket air intake and do not tune for it, it is asking for trouble. You may or may not be fine. In general, you will definitely run lean. The MAF sensor is very sensitive. Link to comment Share on other sites More sharing options...
BoozeRS05 Posted November 7, 2017 Share Posted November 7, 2017 Catless UP and turbo inlet tube should not necessitate a tune, but an air intake would for our cars. It comes before the MAF sensor, and scaling air coming into the motor is very important. Data logging will provide the definitive answers you need with modding and performance though. I have btssm running pretty much all time while driving. EB's Subaru journal - 2005 LegacyGT Wagon & 2014 Forester FB25 (2008 specB - RIP) IG@legacygtliving Link to comment Share on other sites More sharing options...
Spaceman Spiff Posted November 7, 2017 Author Share Posted November 7, 2017 Thanks. I very much like the idea of exploring this btssm. It seems I won't be getting much done at work today. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted November 7, 2017 Share Posted November 7, 2017 I have btssm running pretty much all time while driving. Me too. I have it running in both of our cars at all times. It is a must have for these turbo subies. Link to comment Share on other sites More sharing options...
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