scottmcphee Posted August 14, 2015 Share Posted August 14, 2015 This combination of codes was coming up, cleared a few times, and P0139 kept coming back... so I replaced the rear oxygen sensor and no joy. P0139 and P2096 have come back after several start cycles and a long drive. Next... a front O2 / oxygen / air fuel ratio / AFR (whatever you want to call it) sensor just got ordered and is going in next, when I get it from rockauto. The good thing I guess about doing things sequentially is I received a coupon code from my first order, that I was able to use on the second order just now. I don't mind replacing both, they're still original and it's now 10 years later. FYI This is for a 2006 2.5i SOHC (non-turbo) car. ..by the way, I have a question. My code reader comes back with 3 codes P0139 P0139 P p2096 P What does the trailing "P" mean for some codes? Link to comment Share on other sites More sharing options...
Max Capacity Posted August 14, 2015 Share Posted August 14, 2015 http://legacygt.com/forums/showthread.php/trouble-codes-cels-26113.html Bank 1 is the front O2 That being the last code in the list, I think is the first one to pop up as an issue. The other cel's follow it as they are caused by it failing. the other cel's that deal with timing, bank 1 is the passenger side, bank 2 is drivers side in these cars. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
scottmcphee Posted September 6, 2015 Author Share Posted September 6, 2015 So now the car has it's front O2 /AFR sensor replaced.... and it's still throwing P0139. There's no more O2 sensors on the car to replace. please don't let this be a catalytic converter... What's next on the list before that? Link to comment Share on other sites More sharing options...
apexi Posted September 6, 2015 Share Posted September 6, 2015 Exhaust leak? Link to comment Share on other sites More sharing options...
Max Capacity Posted September 6, 2015 Share Posted September 6, 2015 Oh, I see you have a 2.5i, might be the cat. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
scottmcphee Posted September 7, 2015 Author Share Posted September 7, 2015 Cleaned the MAF sensor with brake cleaner spray that also says it's good for electrical too, and compressed air to blow and dry it out. After that, car had a hard start and idle drops down very low to the point 9f almost stalling, then catches itself before stalling and revs it a bit higher. Runs a bit rough too, but it was doing that for last little while anyway so .... I think I'll check spark plugs next haven't done those in years. Link to comment Share on other sites More sharing options...
JmP6889928 Posted September 7, 2015 Share Posted September 7, 2015 If you used compressed air to clean your MAF, you may have damaged it. It's extremely delicate and you are only supposed to spray it and let it air dry. If you know someone else who has the same car as yours, try their MAF and see if it fixes everything before purchasing one. I've actually seen one that was bent about 30 degrees from using a very strong air source to dry it and needless to say, it never worked correctly again. Link to comment Share on other sites More sharing options...
scottmcphee Posted September 7, 2015 Author Share Posted September 7, 2015 If you used compressed air to clean your MAF, you may have damaged it. It's extremely delicate and you are only supposed to spray it and let it air dry. If you know someone else who has the same car as yours, try their MAF and see if it fixes everything before purchasing one. I've actually seen one that was bent about 30 degrees from using a very strong air source to dry it and needless to say, it never worked correctly again. The fine wires down in the MAF look to be intact after using comoressed air. Not bent or missing. They look cleaner now, and the temperature bulb is also definitely cleaner. I know well enough not to touch them with swabs or anything, figured air was fine because they are built to handle air flowing over them, albeit not 90 psi! I suppose I could electrically test the MAF to check its functioning. You'd think OBD would throw some vicious codes if MAF was busted, not getting that... Looks to be similar to our Subarus: http://troubleshootmyvehicle.com/toyota/1.8L/how-to-test-the-maf-sensor-1 Link to comment Share on other sites More sharing options...
scottmcphee Posted April 21, 2016 Author Share Posted April 21, 2016 I got the BtSSM tool being developed by a member of this forum. Awesome thing. I was able to watch live values of rear O2 sensor... P0139 was not lying... The rear sensor, the new one, appeared to hardly vary from 0.6 volt for the whole drive cycle, according to what the ECM was seeing. So next I unplugged the rear 02 and hooked up my volt meter to it with engine running. Shocked to see that normal wide range of voltages coming from the sensor. Pulling a vaccum line off the intake forced a lean mixture and that 02 sensor dropped like a rock to something around 0.1 volt, as it should. Meanwhile ECM still reporting 0.6 volts. Something fishy going on! I cleaned all the all the grounding points of straps to the engine block and chassis to battery. That did it! Went for a drive and now ECM is seeing and reporting wide ranges of voltages from rear O2 and is very responsive to changing load conditions and pedal inputs. And settles in at around 0.5 volts as its most normal value, as it should. Super pleased about that. Surprised myself how important clean grounding points are. Link to comment Share on other sites More sharing options...
scottmcphee Posted April 25, 2016 Author Share Posted April 25, 2016 Crappola! After a few days... the ECM is seeing a pretty much constant 0.6v from the rear O2 sensor (again)... when I test the actual O2 sensor (in-car and warmed up) with my VOM I see the sensor is actually outputting 0.1 to 0.8 in response to engine load, and induced lean mixture, etc. Like it should. But ECM has become "deaf" to that. So the car codes p0139 again. Something is preventing the true O2 sensor signal value from reaching the ECM or being computed by the ECM correctly. I thought it was poor ground.. It was weird how fixing up those ground lugs had the effect of getting the true output values of the rear O2 seen by the ECM. And now the ECM is just seeing a ghost 0.6v all the time again. Not happy camper. Link to comment Share on other sites More sharing options...
Max Capacity Posted April 25, 2016 Share Posted April 25, 2016 Do you have the service manual ? May be that will help. http://people.csail.mit.edu/ilh/vacation/ 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
scottmcphee Posted April 25, 2016 Author Share Posted April 25, 2016 Yes.. I do have the manuals, thank you. And just to be clear, since this thread goes way back. I'm only seeing p0139 nowadays... the p2096 has not reappeared for long long time. Link to comment Share on other sites More sharing options...
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