MAS, Throttle Body & EFI Services - required?

Hi there,

I have a 2013 Toyota Highlander with 35k miles on it. For my 30k service, they recommended getting Mass air flow sensor, Throttle body and electronic fuel injection services which would total $335. I declined as after doing some general research I knew that this was too expensive and possibly not required. My car just came out of it’s 35k service and I asked if those other 3 services are still required. They said, not required but might make my car perform somewhat better.

They reduced the price to $300, but I still don’t want to pay that much and would prefer to bring it to a local mechanic. But now I’m wondering if I need these services at all and it so, what should they really cost? I do a lot of miles in it as can be seen so if it improves fuel consumption etc I would get the services.

Thanks for the help!

Those parts can indeed gunk up over time and miles driven. But 35 k is pretty low mileage. Unless you are having drivability problems, or your mpg’s has gone down noticeably, me, I’d take a wait and see on this.

I’m assuming you had a dealership do the 30k service. They sometimes use these routine service jobs as a way to upsell some services to you, since you are at that point a captive audience. Hard to say for sure in this case. But if they first said it would cost $335, and now they say it costs $300, doesn’t that sound a little fishy?

That said, if you could be guaranteed what they did nothing, or improved things, $300 isn’t an overcharge for the service. The reason I’d avoid having this done is that you may get unlucky and something that is now working could get damaged in the process.

Waste of money if there’s no performance problems or check engine light.
How does engine performance and mpg compare to when it had, say, 15K miles?
These services generally aren’t helpful until ~100K miles.

What services does the dealer provide for the MAF, throttle body, and fuel injectors? Are these services listed in the Toyota maintenance schedule that is in your glove box, or are they dealer recommendations? If only dealer recommendations, I would pass on them.

I add a can of Seafoam or Chevron Techron to the gas tank on my wife’s 06 Sienna once a year or so to clean the fuel system. The van is 8 years old with no driveability issues. Other than some warranty work I’ve never used the dealer, I prefer my local independent mechanic.

Ed B.

I’d leave the MAF alone, if there are no driveability complaints, no check engine light, and no codes

As for the throttle body, cleaning it every few years is a good idea

But you should easily be able to do this yourself, with a few basic tools and a can of throttle body cleaner

Leave the fuel system alone if there are no complaints

Pure mouse milk in your case. Your car doesn’t have throttle body injection so the throttle body doesn’t meter anything but air. If you feel the need to do something throw in a can of Cheveron Techron. You probably don’t need it but is probably is as good as what the dealer will use and costs about $10.

Waste of money.

Total ripoff in my opinion.

And, in a properly driven 2013 car with 35,000 miles, there’s no way it’d help your car “run better”. I see nothing in this thread that suggests in any way that the engine might be running at anything less than its absolute optimum.

An induction cleaning is not always a ripoff. It’s a case by case basis with a lot of variables involved.

My feeling is that you could probably pass on these services for the time being. They won’t hurt but the cost/benefit ratio won’t be in your favor.

On a one year old properly operating car with 35,000 miles? I’ll have to respectfully disagree on this one, my friend.

If you have $300 to throw away then get the service done. This service is generally just a way to increase the profit margin of a repair shop. I don’t think you need it based on the mileage you stated. Is this service ever needed? Rarely…if if ever.

Never had this done on any car, and my 2007 Toyota does not need it either. Like some posters, I put some fuel system cleaner in the gas tank once a year and have never had a rough running car due to the fuel system problems. My Toyota dealer pushes other things I don’t need. Our 1994 Sentra never had its fuel system serviced from the day we got it till 2012 when we sold it.

We do tank Top Tier gasolines, but any modern gasline has enough detergent in it to keep the system clean.

If some of you had seen the intake that was removed from a Lincoln Town Car that only had about 30k miles on the clock any opinion about induction cleaning not being needed could easily turn into a definite yes.
I saw that one at the Lincoln dealer one day after stopping to pick up some parts and to chat with a buddy who’s a mechanic there and who was in the middle of that operation. There were no symptoms other than a grungy throttle body that was noticed during the 30k miles service. That led to the recommendation for intake removal and that thing was nasty beyond belief.

Additives in the tank will clean the fuel system but will do nothing for the throttle body or IAC as no fuel passes through them and will do very little if anything for EGR clogs.

A can of CRC Mass Air Flow Sensor Cleaner is about $7.50; a can of CRC Throttle Body and Air Intake Cleaner is about $4.00.

That’s how I clean my MAF sensor and throttle body.

The throttle body cleaning is needed about once every few years. My local Toyota dealer halls this “Air induction cleaning” and charges about 136 dollars for it.

Independent mechanic charge about 60-80 dollars and you could do it yourself for a ten dollar investment in throttle body cleaner.

The following point could also be made. It’s claimed by car makers that oil consumption of 1 quart per 1000 miles should be considered normal; a premise I don’t agree with, but…

Assuming the car has 30k miles on it that means the engine has sucked through 30 quarts of oil in its short lifetime; all of that residue ending up on the converter substrate, blowby in the intake manifold courtesy of the PCV, and in the EGR system passages.

While it’s true the throttle body intakes nothing but “air”, assuming that it doesn’t need to be cleaned periodically because of that ignores the fact that a lot of designs plumb in the crankcase ventilation system right behind the TB. That, and the fact there is always valve overlap means there will be deposit laden fumes continuously licking at the backside of the TB.

Case in point, the Atlas I6 in the Trailblazer is well known for often needing throttle body cleanings at a rate of around 30-50k miles, depending on usage type and engine condition. I have owned two so far and both start to show signs of buildup around 50k miles under my type of usage. Upon removing the TB, the evidence is obvious with crud making the TP sticky…

Thanks for all your feedback, appreciate it. (I thought I had flagged my post to email me when a response is made but obviously not!)

I held off on the dealer recommendation (again) especially with him dropping the price 10% without me even asking for it. While I was waiting to pick my car up, I overheard another service guy explaining the same scenario to another customer and why he needed these extra services.

Having said all of that, they have succeeded in planting the seed of doubt in my mind. @98caddy - you’re right when I searched online for how much the raw materials would cost, they came in around $20 - $30 which is less than 10% of what the dealer was going to charge (granted there’s labor included).

I don’t notice any performance problems & there are no lights flashing at me. I think my MPG has slightly dipped but traffic on the freeway where we do our regular work commute has increased somewhat over the past year, so there’s more stop & go.

It sounds like the majority of you folks have said it’s a waste of money to go with a dealer and to instead do it myself or just leave it alone. I’ve zero experience in car maintenance (did I incorrectly call it MAS instead of MAF !) so I might just either leave it be.

The way I’m looking at it right now is, we will have this as a family car for a long time so I’m not expecting to see a huge return when/if we sell it down the road. If avoiding this service for, say another 35k miles will not cause the car to blow up or completely fail then I would think why not wait.

Put it off for another 70k. No harm will be done.
Check your tire pressure once a month (if you don’t already) to save a little gas.