Akasa Posted July 1, 2014 Share Posted July 1, 2014 So it seems like i'm throwing the P2096 CEL. I was driving and I noticed the car stumble a bit, then throw the code; I cleared it, only to have it come back 50 miles later. The reason i'm posting this, is I can't seem to find instances of where people ONLY have an aftermarket (grimmspeed) up pipe installed. I used new gaskets, so I don't think i'd have an exhaust leak. Could this code be sign that I /am/ actually running lean? If anyone has any tips i'd appreciate it greatly. Link to comment Share on other sites More sharing options...
MeoW71 Posted July 1, 2014 Share Posted July 1, 2014 Not really, could be failing rear O2 sensor or a failing cat. Link to comment Share on other sites More sharing options...
Akasa Posted July 1, 2014 Author Share Posted July 1, 2014 What could I do to diagnose this myself then? Link to comment Share on other sites More sharing options...
Max Capacity Posted July 1, 2014 Share Posted July 1, 2014 P2096 - Post Catalyst Fuel Trim System Too Lean Bank 1 replace your front O2 sensor, buy a OEM one or check in here, http://legacygt.com/forums/showthread.php/idea-web-links-saved-various-parts-219238.html 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...
m sprank Posted July 3, 2014 Share Posted July 3, 2014 This code is thrown because the rear 02 and the front 02 are reading the same. The Cat converts O2 to CO and CO2. So, the rear O2 should always be richer than the front O2. When the cat fails it stops converting the O2. So the rear O2 reads close to or the same as the front 02. Code pops, you have a bad cat. Exhaust leak, bad O2 sensor, bad cat are the first 3 things to look for (not necessarily in that order). This is uber simplified, but I hope it helps. Link to comment Share on other sites More sharing options...
Max Capacity Posted July 3, 2014 Share Posted July 3, 2014 Mike are you saying to replace the Front O2 (bank 1) after he verify's there's no exhaust leak ? 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...
Akasa Posted July 3, 2014 Author Share Posted July 3, 2014 I've been measuring my o2 sensors, both front and rear are displaying just around the same. I've noticed that I will temporarily run rich, (this is both sensors, assuming my xgauge is configured correctly), (about 20) then go back to a bit lean (12) most of my idle speed hovers around 13.8-14.3, which I believe is within tolerance. I'm not sure if this is helpful or not. I also torqued the head, crosspipe, up pipe, and downpipe down to factory specs with my torque wrench, using all new gaskets, I wouldn't imagine that there's an exhaust leak, I haven't noticed any tell-tail signs related to an exhaust leak. Upon removal of my stock up-pipe, the cat in the up-pipe looked clean, other than obvious signs of wear and stress from having 82k miles on it, it was clean. It seems almost improbable that it would be the cat even more downstream failing. Link to comment Share on other sites More sharing options...
Max Capacity Posted July 3, 2014 Share Posted July 3, 2014 From the years on here, I have not seen many, if any GT's with bad cat's in the DP. I have seen lots of O2 sensors go bad. Just saying.... 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...
MrTris Posted July 3, 2014 Share Posted July 3, 2014 From the years on here, I have not seen many, if any GT's with bad cat's in the DP. I have seen lots of O2 sensors go bad. Just saying.... Well, if the stock tune runs rich and burns valves, why wouldn't an earlier symptom of that be failing cats, due the the same problem -- running rich? Correct me if I'm wrong, but, isn't running rich the number one way to kill a cadillac converter? ('scuse my South) And if the DP cat is the first one in the series, I assume it'd get the brunt of the richest exhaust, pre-conversion, right? Link to comment Share on other sites More sharing options...
Max Capacity Posted July 3, 2014 Share Posted July 3, 2014 I agree that running rich will kill the cat. I'm not sure the stock tune runs rich and burns valves. I think the burnt valves is more of a timing issue, which if I understand it right causes it t run lean. I'm no expert in tuning so may be someone else will address that. I think running lean will burn valves not running rich. 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...
m sprank Posted July 4, 2014 Share Posted July 4, 2014 Burnt valves is a lean condition. Excess fuel will kill a cat. If both sensors are reading the same it is most likely either a failed down pipe cat or a failed O2 sensor. I would point to the front 02 prior to the rear. I would also clean the MAF just in case. I have seen more failed O2 sensors than failed down pipe cats. But I have had failed down pipe cats too. Link to comment Share on other sites More sharing options...
firehawk618 Posted July 4, 2014 Share Posted July 4, 2014 Burnt valves is a lean condition. Excess fuel will kill a cat. If both sensors are reading the same it is most likely either a failed down pipe cat or a failed O2 sensor. I would point to the front 02 prior to the rear. I would also clean the MAF just in case. All this is true. 10' CTS-V, A6, Airraid, 2.4 upper, ID850's, self tuned. SOLD:06' LGT Wagon. BNR16G, Catless UP, DOWN, Hexmods VB, Hexmods diff bushings, BIG TMIC. Best 0-60: 4.651 by AP 1/4= 13.678@100.73 mph, 1.945 60', Automatic transmission. Link to comment Share on other sites More sharing options...
Akasa Posted July 8, 2014 Author Share Posted July 8, 2014 I've noticed that when I turn my car off without clearing the CEL, the car doesn't like starting up with the CEL on, like it retards the ignition timing. Sometimes it'll start normally, other times it will take several cranks to get the car to fire up, but as soon as I clear the CEL, it fires up normally every time without fail. Thought this would be worth adding. Link to comment Share on other sites More sharing options...
Max Capacity Posted July 8, 2014 Share Posted July 8, 2014 Have you cleaned th MAF ? Have you replaced the front O2 with a OEM unit ? 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...
FknBoss Posted July 8, 2014 Share Posted July 8, 2014 I'd be lead towards the front o2. If it was a failing cat it'd throw a p0420 code. Link to comment Share on other sites More sharing options...
FknBoss Posted July 8, 2014 Share Posted July 8, 2014 When you throw a lean code more often than not the cars computer will compensate with fuel to correct for the lean issue. If you were never really lean then that false lean reading will cause you to run very rich. Link to comment Share on other sites More sharing options...
Max Capacity Posted July 8, 2014 Share Posted July 8, 2014 The O2 Sensors are easy to replace if you have the right socket. Harbor Fright has O2 sockets. I use a screw type hose clamp around mine to keep it from spreading. Spray the old one with PB Blaster and let it sit for a few minutes before you try and remove it. Oh the sensor is behind the plastic panel behind the right front wheel. 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...
Akasa Posted July 8, 2014 Author Share Posted July 8, 2014 I've cleaned the MAF already, I just haven't done anything with either o2 sensor yet. I'd like to verify what exactly is the issue so i'm not throwing money replacing parts that don't need to be replaced. When I removed the front O2 to do the up pipe, it seemed still in working order. I've noticed that my car IS running lean according to both the front and rear o2 sensors. It averages around mid 14's, sometimes a bit rich, sometimes a bit lean, then it'll have a mood swing into the very lean side (20:1ish). They're both displaying around the same AFR. This started happening after I installed my up pipe, so I'm almost thinking that that's causing the lean issue. I'm just starting to get lost at this point. Link to comment Share on other sites More sharing options...
FknBoss Posted July 8, 2014 Share Posted July 8, 2014 Just because the sensor is saying your lean doesn't mean you are if their bad. The reading shouldn't be close between the 2 sensors. Maybe some can check to see what their readings are and if the front is incorrect then replace it. My engine is ripped apart right now so I can help you with that at the moment. Link to comment Share on other sites More sharing options...
FknBoss Posted July 8, 2014 Share Posted July 8, 2014 When it jumps to lean 20:1 that's bad. When it does that try to see if the front o2 voltage is changing. Do you have data logging capability? Link to comment Share on other sites More sharing options...
FknBoss Posted July 8, 2014 Share Posted July 8, 2014 If you don't know Voltage on a lean o2 can drop to .01 volt. 0.45 voltage is perfect. And can rise to .9 rich and that's maxed. Link to comment Share on other sites More sharing options...
Max Capacity Posted July 8, 2014 Share Posted July 8, 2014 I'm also saying sensors don't last forever. Just because it looks ok on the outside...doesn't mean it is on the inside. are there voltage test you can do in the sensor ? The front O2 helps controls fuel flow. If your having fuel flow, like your running lean...replace the front O2. If you are in fact running lean and don't fix it soon...whats the worst that can happen... 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...
FknBoss Posted July 9, 2014 Share Posted July 9, 2014 Try unplugging the front o2 so it runs in open loop and see if the air fuel stays consistent. Should run rich. Link to comment Share on other sites More sharing options...
Akasa Posted July 23, 2014 Author Share Posted July 23, 2014 Thank you for you help everyone, it turns out that it was my front bank AFR sensor. I pulled the sensor to inspect it, and it was burnt pretty badly. Does anyone have any idea what would cause this in the first place? The car is 81k miles old though, with the original sensor. http://i.imgur.com/TJAzXNi.jpg Link to comment Share on other sites More sharing options...
FknBoss Posted July 23, 2014 Share Posted July 23, 2014 Sensors don't last forever. Link to comment Share on other sites More sharing options...
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