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After getting a OBD2 dongle for troubleshooting I noticed my long term fuel trims seemed high. Was often +11 to +14 at idle which from what I read is high. Oddly it often went up one or two points when raising RPM to 2500 but would go down to about +3 on the highway.
Mentioned this to the dealer as still barely under warranty and all they did is update the computers to latest versions and tuning and told me hopefully that would fix it and that is all they wanted to do at the time even after a push. Now it often but not always still idles high but have had the LTFT even go from -13 to +14 on a 15 minute drive. It’s now very inconsistent and even staying negative at times. So went from apparently abnormal and consistent to now just all over the place and even getting getting as low as -18 and as high as +20 in rare cases.
Am I wrong in thinking this is abnormal despite some dealer hesitation. Despite not yet setting a CEL is this something I should be able to force the dealer to address because if it’s an issue I have less than 5000km left before the bumper to bumper warranty expires?
PS I know some of the things I should check like vacuum leak, dirty MAF, etc but given it is under warranty still my big concern is this an issue as I think and one I can get them to address for free without me wasting time.
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Replies
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Without a CEL or some sort of other drivability concern, you won’t be able to get a dealer to address this. Im not going to say it’s normal, I haven’t yet had to monitor 2.5L fuel trims but, w/o a code set, I would feel fine. Not to mention if you have had them look at it for that concern already, you’re covered if something happens reasonably out of warranty.
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Agreed. This is not normal, but without a CEL or performance issues, the warranty won’t help.
Make sure you have an OEM air filter and it’s correctly installed.
[quote=”relative4″ post=188030]Agreed. This is not normal, but without a CEL or performance issues, the warranty won’t help.
Make sure you have an OEM air filter and it’s correctly installed.[/quote]
Well have been finding my fuel efficiency hasn’t been the greatest lately but it’s not too far off so thought *maybe* it was my driving but maybe it’s the fuel trim.If warranty won’t cover it does anyone have suggestions on what it might be. I would like to trace it down and fix it as I find it unsettling or at least find the cause and if it’s a failing sensor force them to replace it.
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I would not base my concerns from the readings from a OBD dongle ..
Or should I say, tablet or phone used to read it.I have one installed, but get different readings from 2 different tablets and a smart phone.
According to one set of readings, the combined fuel trims were above +30, which I knew were incorrect.
The second placed them + / – 2
Best to use a proper scanner and proceed from there.[quote=”nightflyr” post=188033]I would not base my concerns from the readings from a OBD dongle ..
Or should I say, tablet or phone used to read it.I have one installed, but get different readings from 2 different tablets and a smart phone.
According to one set of readings, the combined fuel trims were above +30, which I knew were incorrect.
The second placed them + / – 2
Best to use a proper scanner and proceed from there.[/quote]
Never heard of this before. Nightflyr, would you be willing to provide details on what model dongle you’re using, and what devices/apps got accurate/inaccurate results?OP, what dongle, device, and app are you using?
[quote=”relative4″ post=188034][quote=”nightflyr” post=188033]I would not base my concerns from the readings from a OBD dongle ..
Or should I say, tablet or phone used to read it.I have one installed, but get different readings from 2 different tablets and a smart phone.
According to one set of readings, the combined fuel trims were above +30, which I knew were incorrect.
The second placed them + / – 2
Best to use a proper scanner and proceed from there.[/quote]
Never heard of this before. Nightflyr, would you be willing to provide details on what model dongle you’re using, and what devices/apps got accurate/inaccurate results?OP, what dongle, device, and app are you using?[/quote]
Yes please more details as I tried to different apps an where consistent and tried on two other cars and the other cars where less then +/-4 on the long term.I am using Torque with Veepeak ELM327 Bluetooth module and using a Nexus 6P with all latest updates.
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Never heard of this before. Nightflyr, would you be willing to provide details on what model dongle you’re using, and what devices/apps got accurate/inaccurate results?
[i]Yes please more details as I tried to different apps an where consistent and tried on two other cars and the other cars where less then +/-4 on the long term.
I am using Torque with Veepeak ELM327 Bluetooth module and using a Nexus 6P with all latest updates.[/i]BAFX Products 34t5 Bluetooth OBDII Scan Tool for Android Devices
As to devices used:
Samsung Galaxy Tab 3 7.0
Samsung Galaxy Tab E lite 7.0
Samsung Media player 5.0
The most accurate is the E lite.
The least is the Tab 3 7.0
TORQUES App[quote=”nightflyr” post=188040]Never heard of this before. Nightflyr, would you be willing to provide details on what model dongle you’re using, and what devices/apps got accurate/inaccurate results?
[i]Yes please more details as I tried to different apps an where consistent and tried on two other cars and the other cars where less then +/-4 on the long term.
I am using Torque with Veepeak ELM327 Bluetooth module and using a Nexus 6P with all latest updates.[/i]BAFX Products 34t5 Bluetooth OBDII Scan Tool for Android Devices
As to devices used:
Samsung Galaxy Tab 3 7.0
Samsung Galaxy Tab E lite 7.0
Samsung Media player 5.0
The most accurate is the E lite.
The least is the Tab 3 7.0
TORQUES App[/quote]
Very strange as the phone/tablet should have no major impact other than maybe the amount and speed of data it can handle.Sent from my Nexus 6P using Tapatalk
I can’t see any reason why the device you are using would have any effect on the readings, other than perhaps to impart a slight delay in real time displays.
I use a generic ELM bluetooth adapter with either my Galaxy note4 phone, or my Lenova tablet, and have not noticed any difference in readings between the two devices.
I had some crazy fuel trims on my Accord, going as high as +30, and as low as nearly -50 combined. Had NO check engine light, though I did have performance issues. Turned out to be a bad O2 sensor, so you might want to look at what that is doing when you get those changes in fuel trim.
[quote=”cj1″ post=188066]OP- if Malibu is flex fuel check that fuel sensor is accurately reflecting type of fuel.[/quote]
Not flex fuel and because of a quirk in gas supply we typically don’t have ethanol in our gas at all.Sent from my Nexus 6P using Tapatalk
[quote=”Tomh” post=188079]I can’t see any reason why the device you are using would have any effect on the readings, other than perhaps to impart a slight delay in real time displays.
I use a generic ELM bluetooth adapter with either my Galaxy note4 phone, or my Lenova tablet, and have not noticed any difference in readings between the two devices.
I had some crazy fuel trims on my Accord, going as high as +30, and as low as nearly -50 combined. Had NO check engine light, though I did have performance issues. Turned out to be a bad O2 sensor, so you might want to look at what that is doing when you get those changes in fuel trim.[/quote]
I checked the O2 sensor and it is reacting but not in a nice sign wave I see at times but sometimes sticks near to top or bottom of the scale for a while which isn’t like I have seen in some videos. But not sure if this is the cause of my issues or a symptom. Who did you tell yours was bad?Sent from my Nexus 6P using Tapatalk
Mine was sticking very high, and very low. After a bit, I took notice of the fact that when I gave the engine full throttle, it would clean up and run great. At full throttle, it is in open loop, not paying attention to the O2. This strongly pointed me in the direction of something with the O2, it’s wiring, or the ECU.
From there, I unplugged the O2, forcing the computer into open loop, and the car ran fine like that. A little low on power from running too rich, but no issues with how it drove. At that point, I was pretty positive the problem was in that system. Knowing that it was probably a 20 year old O2 sensor, and it had an aftermarket extension on the wiring, I went for those two things first. Checked the wiring, and made repairs as necessary, though it didn’t appear that there was enough damage to the wiring to cause any shorts, but I made sure of it. That didn’t fix the problem, so I swapped in a new OEM O2 sensor, figuring that the one that was there wasn’t good, even if it wasn’t the problem. Turned out that was the whole issue.
There are ways to test the O2, and it’s wiring, but in general, I’d say if the O2 is more than a couple of years old, you probably aren’t wasting money to replace it with a new OEM unit, even if that doesn’t turn out to be your problem.
With the readings sticking high, or low for any real period of time, I would be suspect of the sensor though.
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