I have a 2012 Buick Lacrosse with 3.6 V6 engine and 120K miles. A recently purchased a new scanner per Scotty's recommendation and my Long Term Fuel Trim 2 is -14% or so at idle. All the other trim values, short and long, are between -3% and +3% at idle. Car is very well maintained (spark plugs replaced and throttle body cleaned at 110K miles). Car runs well. My question- is the -13% reading okay or should I take some corrective action?
When were the injectors ever cleaned on this 10 year old vehicle?
I used to use Lucas' fuel additive a few times per year, but nothing within the past +3 years. What do you recommend? Thanks for your advice!
I recommend the injectors be removed and pressure solvent cleaned by a professional, instead of wasting $12 pouring a useless chemical in your gas tank.
Your ECU found that the correct mixture is achieved when it injected -13% less fuel than what it expected based on sensors.
Clean MAF and MAP, check IAT readings - very rarely it's even just a dirty engine air intake filter.
Also, sometimes it's caused by intake valve having too much carbon buildup, that 3.6 VVT is a GDi engine.
Although I wouldn't worry about -13% too much - it's better to try and get to the root of the issue now and not later.
