I recently got a new scan tool that does live data and had a chance to look at the short and long term fuel trims on both banks of the V6 engine on my 2007 Honda Pilot with 162,000 miles. Can anyone tell me if the numbers I am getting are bad?
Short term on both banks seems to track one another- At idle the numbers are +9% to +14%
Long term on both banks seems to track one another - +1% to 0.1%
I was thinking of bringing to a mechanic for a fuel injector cleaner service like Scotty mentioned on one of his videos. Not sure if these numbers suggest that would be helpful or not. The engine does not run rough and there are no trouble codes. Just curious.
are you sure you didn't confuse short term and long term? They seem switched.
No. That's what the scan tool showed.
Weird. Well the STFT are impossibly bad
I googled this and saw an article on https://www.mechanic.com.au/news/understanding-short-term-and-long-term-fuel-trims1
It seems that +10% short term fuel trim is OK and a 0-1% long term fuel trim is also OK This is what it says, in part:
Short-term fuel trim values
Assuming that the engine is in excellent mechanical condition, and that all sensors implicated in metering both intake air and fuel, short-term fuel trim values should generally be between positive 10%, and negative 10% when the engine is running at a steady speed. Note though that since sudden changes in the engine speed can cause short-term fuel trim values to fluctuate wildly, all fuel trim values should be taken at a minimum of at least three steady engine speeds, these being at idle, at about 2500 RPM, and at about 3500 RPM. Note also that fuel trim values should only be taken when the engine had been running at the above speeds for at least 30 seconds.
Long-term fuel trim values
Ideally, long-term fuel trims should be at, or close to 0% when the engine is running at a steady speed. However, while changes to the engine speed will (and must) produce changes in the long-term fuel trim value, this value should return to a point close to 0% when the engine speed steadies. Note that if the long-term fuel trim values fluctuate in a pattern that resembles the fluctuations of the short-term fuel trim values suspect a defective catalytic converter.