Car hesitates upon acceleration at low speeds

I have a 2002 Toyota Highlander that sort of chokes. At random times while driving, the car hesitates on acceleration, chokes a little, and then continues to accelerate. It is an automatic transmission but it feels like I can feel the shift in gears. usually happens at low speeds (20 mph). no matter time of day or warm up period. I have been having regular maintenance at dealer. there was a caution note that I would need spark plugs replaced… is this it? a result o f needing new spark plugs? or something else?

It might be. You need them anyway, it makes sense to get them and see what happens.
When a sparkplug gap grows, it takes more of a voltage spike to create the arc. When it grows too much, it can no longer reliably fire reliably under load conditions.

And I’d recommend finding a reputable independent shop. You’ll save a ton of money over the dealership.

Let us know how you make out. We do care.

That can easily come from old spark plugs. If they’re due there’s no reason not to do that first.

Is the check engine light on?

Inspect the air filter is installed properly. Make sure the air filter is of the normal variety like the one installed at the factory. Some aftermarket air filters contain oil in the filter media which will contaminate the mass air flow sensor. Clean or replace the mass air flow sensor if this is the case.

Thanks all! Check engine light is not on. I will follow up and keep you posted!

Turns out the gears are slipping. Specifically from 2nd to 3rd gear slips but not every time… Dealer says transmission needs to be rebuilt at $5000. Neighbor has suggested getting a second opinion at a place like Aamco. Thoughts?

My thought is that you should ignore your neighbor’s suggestion unless you want to be told that you need a new/rebuilt transmission–even if there is only a less severe problem. Chain transmission places are notorious for pushing rebuilding jobs when much less expensive repairs are all that is needed.

Yes, you need a 2nd opinion, but it should come from an independent transmission shop that has been in business for several years. Ask friends, co-workers, relatives, and neighbors (other than the one who recommended Aamco) for recommendations regarding indy transmission shops.