Next time you put gas in it, try a different station and maybe put a higher octane gas in it. Worth a shot.

 

That's helpful. I fill it up at Costco. Put in 93 Octane. I'll try another gas station like Mobil or Shell.

 

Could it be the battery that is getting weak?

 

Didn't think of that but it's possible. I drive it regularly and it does sit outside on the driveway but I warm it up every morning.

Dealer said not to use Costco Gas. Thoughts on that?

 

Dealer suggested not to put 93 octane gas from Costco. He suggested it might be causing the sputtering before engine starts.

Thoughts on this.

 

 

Dealer is full of cr--. Costco gas meets Top-Tier standards for detergent content recommended by most car manufacturers. (see www.toptiergas.com) The gasoline itself (without the detergent additives) is the same as in all other stations in your area - if one station got bad gas, likely several did. All brands are serviced from the same pipelines/distribution system. The detergents are added to the tanker delivering the gas or into the tank as the delivery is made. Very few gasoline brands meet top-tier standards, as adding an effective amount of detergent costs $$$, and gasoline retailers know cheap American drivers will drive 10 miles to save a penny a gallon.

 

See my reply to your previous post.

 

Costco gas is all good for mine.

 

Used regular and premium for several years at Costco

 

Costco has top tiered gas so they should be good. I just wish there was one close to me LOL

 

I think it could be the air-fuel mixture or one or more injectors acting up. Try using an injector cleaner of good quality, if this is no help then you'll have to move to the computerized air-fuel mixing

 

I have had a sputtering start once in 2 years. It was similar to what happened twice in 8 years with a Highlander I had before. In all cases it was around the same temperature just in the morning just above freezing temperatures but the overnight was colder. I suspect that a combination of sensor temperature not being aligned with the required air mixture for start could be the problem. But I see no way to try and get the dealer to reproduce the problem. Maybe a ODB2 logger would help.