P2195 and P2096 - 2009 LNF Sedan
11-12-2015, 10:39 AM
#26
I dont see an issue with the LTFTs being near 0 like that. The STFTs do bounce around, you'll see spikes to +15 or -15 usually when you let off the gas, under engine load sounds weird though.
Command A/F is as I explained in the previous post. Its what the car's A/F goal is. This changes depending on driving conditions. I keep that with A/F so you can compare what the car is "commanding" the engine to do vs what your actually reading for air/fuel ratio.
Im wondering if your Fuel trims do need some sort of adjustments. There could be a case that when your cruising under light load, your LTFT may drift negative and then when your underload (accelerating) it goes postive causing your LTFT to balance out around 0. This is one way you could be running lean but not seeing the symptom. I will accelerate in my car on the way home (on a stock tune) to see if I see +15 STFT. My LTFT is floating between +3 and +5, due to cold weather.
Command A/F is as I explained in the previous post. Its what the car's A/F goal is. This changes depending on driving conditions. I keep that with A/F so you can compare what the car is "commanding" the engine to do vs what your actually reading for air/fuel ratio.
Im wondering if your Fuel trims do need some sort of adjustments. There could be a case that when your cruising under light load, your LTFT may drift negative and then when your underload (accelerating) it goes postive causing your LTFT to balance out around 0. This is one way you could be running lean but not seeing the symptom. I will accelerate in my car on the way home (on a stock tune) to see if I see +15 STFT. My LTFT is floating between +3 and +5, due to cold weather.
The following users liked this post:
splash (11-12-2015)
11-12-2015, 10:49 AM
#27
New Member
Thread Starter
Well I'll do like you said firehawk and check the EVAP solenoid and MAF. My tuner maintains that it is not the tune and there is an issue elsewhere in the car. He said that with LNF's, they use the O2 sensor for closed loop feedback to control feeling. He also said that it's the original O2 sensor on the car. It may very well be that the sensor itself is really just bad. I'll go driving again today and see what my fuel trims are saying. But I also think that a good idea would be to just replace the sensor.
Cudajoe, under engine load the STFT is supposed to be around 0 correct? Isn't it being at 15 a major problem?
Cudajoe, under engine load the STFT is supposed to be around 0 correct? Isn't it being at 15 a major problem?
11-12-2015, 10:59 AM
#29
New Member
Thread Starter
Cruising 70 down the highway I'm seeing between -3 and -5 vacuum on a straight highway. At idle I'm seeing -17 or -18. Could this perhaps point that it is in fact the purge solenoid causing an issue?
11-12-2015, 11:04 AM
#30
Senior Member
iTrader: (6)
Well I'll do like you said firehawk and check the EVAP solenoid and MAF. My tuner maintains that it is not the tune and there is an issue elsewhere in the car. He said that with LNF's, they use the O2 sensor for closed loop feedback to control feeling. He also said that it's the original O2 sensor on the car. It may very well be that the sensor itself is really just bad. I'll go driving again today and see what my fuel trims are saying. But I also think that a good idea would be to just replace the sensor.
Cudajoe, under engine load the STFT is supposed to be around 0 correct? Isn't it being at 15 a major problem?
Cudajoe, under engine load the STFT is supposed to be around 0 correct? Isn't it being at 15 a major problem?
11-12-2015, 12:26 PM
#31
New Member
Thread Starter
The O2 sensor is throwing check codes. Code P2195 and P2096. P2195 is the O2 sensor being stuck rich. Which leads me to believe that maybe it is just that sensor.
11-12-2015, 02:40 PM
#33
Yes, front and center on the manifold.
Wouldn't hurt to rule that out.
FWIW I"ve been doing a lot of logging to get my MAF scaling right.
I can have it all set, drive to work. LTFT's will stay +-3. Don't touch a thing. Drive home and then LTFT will goto +-6 or 7.
I'm getting close to being done.
What Cudajoe says makes complete sense though. Perhaps cruising is good enough to keep LTFT's around zero but that doesn't necessarily mean that things are right overall. It's just a good quick indicator that things are ok or not though generally.
11-12-2015, 04:58 PM
#35
Senior Member
iTrader: (6)
Yes, front and center on the manifold.
Wouldn't hurt to rule that out.
FWIW I"ve been doing a lot of logging to get my MAF scaling right.
I can have it all set, drive to work. LTFT's will stay +-3. Don't touch a thing. Drive home and then LTFT will goto +-6 or 7.
I'm getting close to being done.
What Cudajoe says makes complete sense though. Perhaps cruising is good enough to keep LTFT's around zero but that doesn't necessarily mean that things are right overall. It's just a good quick indicator that things are ok or not though generally.
Wouldn't hurt to rule that out.
FWIW I"ve been doing a lot of logging to get my MAF scaling right.
I can have it all set, drive to work. LTFT's will stay +-3. Don't touch a thing. Drive home and then LTFT will goto +-6 or 7.
I'm getting close to being done.
What Cudajoe says makes complete sense though. Perhaps cruising is good enough to keep LTFT's around zero but that doesn't necessarily mean that things are right overall. It's just a good quick indicator that things are ok or not though generally.
11-12-2015, 07:50 PM
#37
Senior Member
iTrader: (6)
Yes, disconnect it. If you cap it the ECU thinks its still functioning. I'm surprised it hasn't set a code. Also you need to drive 20+ miles between tune and adjustment to help with getting the trims dialed it.
11-12-2015, 09:53 PM
#38
so just to follow up on what I said I would do. Im on the stock tune right now with my all seasons (winterized the car). My current modifications are ZZP upper Charge pipe, K&N intake, Treadstone TR8 intercooler, High flow catted 3" downpipe, forge BPV.
LTFTs are between +3 and +5 indicating im slightly lean but overall satisfactory. STFT during 100% acceleration from a redlight - partial throttle from first into second STFTs did not go above or below +3 and -3. 100% throttle in 2nd gear and 3rd gear, STFTs stayed around 0 with a flash to +3 or -3 every now and then.
Yeah, I think a super negative/ positive STFT under load is very strange and should drive the LTFT negative eventually. Again it maybe balancing out with a positive STFT under cruise. Could these symptoms be from a bad O_2 sensor? I cant say. The only thing you can do since the car was purchased with a tune is throw parts at it and try analyzing the syptoms (or get HPtuners and data log the car). Padlock is known on here, I remember him posting quite a bit.
I think from experience anyone who tunes from their perspective does no wrong
but thats just me thinking common sense. If you had the factory tune, you'd see if the syptoms follow to the factory tune or not. That would answer the question immediately if it were the tune. whats wierd to me is you never had a problem until last month. Maybe O_2 sensor is the way to go
My car has 88k miles, never changed the O_2 sensor. Its been tuned for 45k miles.
LTFTs are between +3 and +5 indicating im slightly lean but overall satisfactory. STFT during 100% acceleration from a redlight - partial throttle from first into second STFTs did not go above or below +3 and -3. 100% throttle in 2nd gear and 3rd gear, STFTs stayed around 0 with a flash to +3 or -3 every now and then.
Yeah, I think a super negative/ positive STFT under load is very strange and should drive the LTFT negative eventually. Again it maybe balancing out with a positive STFT under cruise. Could these symptoms be from a bad O_2 sensor? I cant say. The only thing you can do since the car was purchased with a tune is throw parts at it and try analyzing the syptoms (or get HPtuners and data log the car). Padlock is known on here, I remember him posting quite a bit.
I think from experience anyone who tunes from their perspective does no wrong
but thats just me thinking common sense. If you had the factory tune, you'd see if the syptoms follow to the factory tune or not. That would answer the question immediately if it were the tune. whats wierd to me is you never had a problem until last month. Maybe O_2 sensor is the way to goMy car has 88k miles, never changed the O_2 sensor. Its been tuned for 45k miles.
Last edited by CudaJoe; 11-13-2015 at 01:37 PM.
11-12-2015, 11:56 PM
#39
New Member
Thread Starter
I guess in that case then I will just go with the sensor. I guess I'm bound to figure out the problem eventually. As long as I don't really get into boost am I doing any damage to the car?
11-13-2015, 09:05 AM
#40
New Member
Thread Starter
I did some more reading this morning. The long term fuel trim is -.7 on this cycle (approximately 400 miles since I reset the code.) Does that point to anything?
11-13-2015, 09:33 AM
#41
averaging on the rich side is safer for the car. underload, extreme positive or negative STFT points to some sort of vac leak/ boost leak, or maybe a failed sensor. But the LTFT should eventually follow suit after a bit. Does the car hold a +18/-18 STFT during acceleration or just flash to it and back?
11-13-2015, 01:17 PM
#44
So for example if the car is commanding 12.0 afr at whatever load/throttle position but isn't seeing it that's where your STFT's come in. It's trying to do what it can to achieve 12.0.
Does that make sense?
I am going to suggest instead of throwing a bunch of parts at the car you pick up a HP tuners cable. Yeah they're a little spendy but worth every penny.
With that cable + laptop you can do some serious logging, post those logs here and we could be a bit more help.
With the scangauge it's great for instant info but it's very hard to sit there and stare at it while driving.
11-13-2015, 01:20 PM
#45
I am doing at a minimum of two 10 mile trips before making any changes.
I am at the point now where I am going to leave it in for a few days, few hundred miles before any more adjustments.
Thanks for the info, I will start a new thread if I have any more questions regarding my tuning.
OP, back to you!
11-13-2015, 01:36 PM
#46
At wide open throttle the CMD AFR should be like 12.0 or whatever its set too. The AFR reading should closely match that (lets say 11.9 for practice). If this is true and we plug in the numbers to the equation, you should see.
((11.9 / 12.0) - 1) x 100% = -0.8% STFT.
In your case....
((14.2 / 12.0) - 1) x 100% = +18.3% STFT.
If the latter is your case, then heres the situation. Your engine is running slightly towards the richer side of the stoichiometric Air/Fuel Ratio but not by any means considered safe for WOT. CMD AFR should be like 12-13 or something. You can't quote me on that but it should be some considerably lower # than 14.0. I can check mine under stock tune.
The reason your LTFT may appear normal is we dont drive to and from work like we are trying to win the Grand Prix. your not at 100% throttle all the time so you wouldnt see a big change in the LTFT. partial throttle AFR is still pretty much 14.7 for AFR CMD.
I dont think whether you had HPtuners vs looking at some data on the scan guage is going to help much more. HPtuners will give you a look at the air load tables and stuff etc.. Only means something if you have some decent exposure to tuning software before. There is a HPtuners forum where you could compare tables to see whats been changed but its like reading tea leaves for anyone new to the stuff. lol.
Hptuner data logging will tell you the same thing, + STFTs under load. If an O_2 sensor is inexpensive, i'd at least try that before buying HPtuners and teaching myself about tuning.
11-13-2015, 05:37 PM
#47
Senior Member
iTrader: (6)
Whatever the ecu is set to command is what it's trying to do. That is adjustable via the tune.
So for example if the car is commanding 12.0 afr at whatever load/throttle position but isn't seeing it that's where your STFT's come in. It's trying to do what it can to achieve 12.0.
Does that make sense?
I am going to suggest instead of throwing a bunch of parts at the car you pick up a HP tuners cable. Yeah they're a little spendy but worth every penny.
With that cable + laptop you can do some serious logging, post those logs here and we could be a bit more help.
With the scangauge it's great for instant info but it's very hard to sit there and stare at it while driving.
So for example if the car is commanding 12.0 afr at whatever load/throttle position but isn't seeing it that's where your STFT's come in. It's trying to do what it can to achieve 12.0.
Does that make sense?
I am going to suggest instead of throwing a bunch of parts at the car you pick up a HP tuners cable. Yeah they're a little spendy but worth every penny.
With that cable + laptop you can do some serious logging, post those logs here and we could be a bit more help.
With the scangauge it's great for instant info but it's very hard to sit there and stare at it while driving.
11-13-2015, 06:47 PM
#48
New Member
Thread Starter
I am getting a rich code for the primary O2 sensor. Where did you find them for $70 ECaulk? AutoParts stores around me are asking $110 for them and I can't even find one online. Where did you find them for $70?
