Markbo Posted November 21, 2014 Share Posted November 21, 2014 OK besides my upstream O2 sensor code (already changed out) I also got P0171 Bank 1 lean indicating a vacuum leak. I finally got my fog machine hooked up this afternoon (just try finding fog machine juice after Halloween!) and found nada. Hooked it up at the air intake after the intake box/MAF, which by the way I cleaned yesterday. It was pretty black. I tried it just sitting and also running... nothing. It was in a fairly dark garage with flashlights so any wisp of smoke would be readily visible. Soooo... next step I guess is to check the MAF. How do I do that? ETA: Forgot to mention, yesterday I sprayed Brakleen all around under the hood and never heard RPMs go up. Tried it around every air flowing and vacuum hose I saw. And yes it was the flammable kind. Link to comment Share on other sites More sharing options...
apexi Posted November 22, 2014 Share Posted November 22, 2014 Since no one has replied yet here's some pages from the FSM with maf sensor values. Link to comment Share on other sites More sharing options...
spec.B452 Posted November 22, 2014 Share Posted November 22, 2014 http://easyautodiagnostics.com/misc-index/maf-sensor-test-basics-1 Good instructions here. Get a can of maf cleaner from an auto parts store. Link to comment Share on other sites More sharing options...
Markbo Posted November 22, 2014 Author Share Posted November 22, 2014 Thanks for those guys. Already cleaned the MAF. Dont have a scanner but I do have a muli meter. Hopefully I can find the right data for a Subaru MAF Link to comment Share on other sites More sharing options...
apexi Posted November 22, 2014 Share Posted November 22, 2014 I know you said that you did a smoke test, but I wonder about that T under the intercooler that people are always having problems with. I wonder if you'd be able to see smoke coming from that vacuum line since it's under the intercooler? Link to comment Share on other sites More sharing options...
Markbo Posted November 22, 2014 Author Share Posted November 22, 2014 Well i cant be 100% sure except that I did it in a dark garage using a flashlight. If there was the slightest whisp of smoke anywhere I think (hope) I would have seen it. I did look under the TMIC as well as I could from both sides and saw nothing. Since I am not throwing a MAF code I think it probably is indeed a vacuum leak. Maybe my little fog machine didnt have enough oomph...though I didnt see anything with it running either. Link to comment Share on other sites More sharing options...
spec.B452 Posted November 24, 2014 Share Posted November 24, 2014 It is definitely worth the 15 minute job to pull your intercooler and check\ reinforce the lines going to the blue tee. Seat the lines as firmly as you can and then zip tie them in place. I actually double zip tied them because the failures were annoying me. If any of.the hoses feel brittle or suspect, replace them. The zip tying applies to both ends of the hoses. Link to comment Share on other sites More sharing options...
Markbo Posted November 24, 2014 Author Share Posted November 24, 2014 I swapped out all the hoses when I put the new turbo in. I think all yhe hoses were zip tied. They should have been, but of course something could have been missed. And I just put on a new, bigger TMIC. I guess I can pull it all apart...will the car run without the TMIC hooked up? Link to comment Share on other sites More sharing options...
spec.B452 Posted November 24, 2014 Share Posted November 24, 2014 No way it would run without the Ic unless you plumbed direct from the turbo output to the throttle body, but I wouldn't do that. Link to comment Share on other sites More sharing options...
Energyblue98 Posted November 24, 2014 Share Posted November 24, 2014 Make sure you're running a stock filter and not a K&N filter or anything.. had this problem not too long ago. If the maf is clean/new and you have a stock filter with no vacuum leaks. then 99% sure it's the 02 wideband sensor. Link to comment Share on other sites More sharing options...
Markbo Posted November 24, 2014 Author Share Posted November 24, 2014 I just changed the upstream O2 sensor wigh a Denso. Stock filter & cleaned the MAF. Any other ideas? Link to comment Share on other sites More sharing options...
jhawk222 Posted November 25, 2014 Share Posted November 25, 2014 Check your up pipe.......I was throwing the p0171, changed the O2 sensor, no luck, cleaned the maf, no luck, the problem turned out to be a crack in the up pipe just before the O2 causing the lean condition. Link to comment Share on other sites More sharing options...
Markbo Posted November 25, 2014 Author Share Posted November 25, 2014 Ill che k but its a new up. Link to comment Share on other sites More sharing options...
Markbo Posted November 26, 2014 Author Share Posted November 26, 2014 I used soapy water and sprayed everything I could see and didnt see any bubbles develope bue CEL/flashing cruise is still on and its idling rough. Im going to try to get these 2 gauges installed and take it to a shop for smoke test/diag. I have looked up gauge install/wiring how to's and there is a lot of conflicting advice. Not sure what Im gonna do there. Link to comment Share on other sites More sharing options...
R32 Posted November 29, 2014 Share Posted November 29, 2014 Had this issue as well. Kept popping up. Replaced MAF and OEM intake. Did the smoke test, couldn't find leaks. Ended up tuning the car. It's been perfect since. Link to comment Share on other sites More sharing options...
Markbo Posted November 29, 2014 Author Share Posted November 29, 2014 I have an aftermarket intake and no scanner to test the MAF. i sure hate to take $150 of the Christmas budget for a part I dont know is bad. Link to comment Share on other sites More sharing options...
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