Causes of occasional hesitation?

My car has 143K miles, mostly freeway driving, and I've followed the standard maintenance items in the owner's manual and replaced the spark plugs at 140K. I've occasionally noticed some hesitation upon acceleration from a dead stop, but not all the time. Mileage is a bit lower than when it was brand new (52 mpg vs 45), but I attribute that to age and the Michelin Premiere tires.

I've seen the how-to videos for cleaning our the EGR and cooler, but I don't have a good way to get under the car (no ramps or jackstands) and would rather go to a shop to have it done. Any recommendations for a local place that can do this? I split time between SF and SJ.

Or might there be other causes for this behavior? The sparkplugs didn't look terrible (to my eye). Oil and coolant levels are steady, so I don't think I'm burning oil.

On a separate note, I've lurked here for a few years, learning a goodly amount from everyone, but this is the first time I needed to post. All the info is greatly appreciated.

 

I bought the spark plugs from RockAuto, a set of Denso SC20HR11. Never changed plugs before, but it went pretty well. While I did drop something (isn't that always the case?), I was able to fish it back out with chopsticks.

I think I can handle doing a throttle body and EGR pipe cleaning.

There's a local mechanic I've used for years to do my oil, coolant, and brake fluid changes, so next time I do an oil change, I'll ask if he's able/willing to clean out the EGR areas I can't get to. If not, Luscious is probably the next stop.

At 140K, does the water pump need changing?

 

OK, I'll make a note to get the pump, thermostat, coolant, and brake fluid sorted at 150K. My local mechanic apparently doesn't have access to TechStream to do the brake fluid flush.

As for cleaning the EGR pipe, it sounds like most folks recommend using carb cleaner or possibly Oxiclean. Has anyone tried Barkeeper's Friend, since the pipe is stainless?

 

Finally got around to cleaning the throttle plate. There were some additional clips on the far left side of the air box, so I couldn't fully remove it easily, but I did manage to get to the throttle plate. I had less luck with the EGR pipe. I only have a stubby 10 mm open wrench, so lacked enough leverage (or arm strength ) to loosen the bolt. Going to have to borrow one from a friend next time.

The plate was a bit grimy, so glad it's nice and clean now. I also found that somehow, I've lost the cap to the engine coolant reservoir. I topped off some coolant about 2 weeks ago, so maybe I thought I had put it back on and it actually fell off somewhere into the engine? Coolant level is fine and I've driven the car w/ no issues, but definitely a facepalm moment.

 

And with the appropriate wrench, I was able to remove the EGR pipe and clean it out. There was a layer of debris, but it came clean rather easily. Sprayed some carb cleaner, used a brass pipe brush, and it was clean in minutes. Also wiped out the surrounding areas I could see. This past week, I haven't noticed any hesitation in the car since cleaning the throttle plate, so maybe that's all the car really needed.

 

I don't have a scan tool, but know a fair number of gearheads at work who do. Will have to check if one of them has an appropriate reader they can let me borrow.

Car is otherwise fine. Doesn't burn oil and just runs like it should. Will likely make an appointment with Luscious to do all the work I can't do, maybe sometime next month when life is a little less crazy.