Lean Long Term Fuel Trim (1 Viewer)

[ExpeditionMan]

Took my 2013 LX570 (139k) on a long highway road trip (~2k miles) recently and monitored the short and long term fuel trims during it. I was disappointed to see long term fuel trim hovering around +7 on both banks. My short trim was +/- 2 off nominal. Does anyone else track their fuel trim? Do you see a similar difference between stft and ltft, especially as a lean condition like mine? The only other wrinkle is about a week before the trip I completed extensive maintenance including: full cooling system, spark plugs, air cleaner, PCV, and gasket for throttle body. I would have expected the ECM to eventually normalize after a number of miles and run cycles. Is there an adaptive value reset I can perform?

No check engine lights.

 

[TeCKis300]

I would say +7 is nothing to worry about and in the realm of normal.

The good thing here is that each back handles their trim discretely. That they both agree is a good thing and the system is working fine. Sure, could be normal wear of common parts like MAF, intake, fuel pump, or more likely none of that and fuel composition, atmospheric conditions, or just normal.

 

[ExpeditionMan]

I would say +7 is nothing to worry about and in the realm of normal.

The good thing here is that each back handles their trim discretely. That they both agree is a good thing and the system is working fine. Sure, could be normal wear of common parts like MAF, intake, fuel pump, or more likely none of that and fuel composition, atmospheric conditions, or just normal.

I've always read and observed that +/- 5 off nominal is ideal. Heck my 26 year old land rover runs +/- 2. I've read some tundra forums have had issues with this and had ECM reflashed from Toyota... or had their fuel pumps replaced.

 

[ExpeditionMan]

Bumping to top for thoughts. Is there a way to have the ECM "relearn" based on recent maintenance? Perhaps leaving the battery disconnected for several minutes?