Replacing the Mass Air Flow Sensor & Cleaning the Throttle Body

No difference. Use the procedure for the 03.

 

The MAF is very easy to get to, sits right on the air cleaner housing in front. Cleaning the TB isn't normally anything more than sticking a rag with throttle body cleaner down into the TB and wiping it around the inside of the bore and the edges of the throttle butterfly. You want to avoid getting TB cleaner on the MAF sensor, but if you've taken the air cleaner off and/or haven't put the new MAF in yet, that's easy to avoid.

If you search around, you will find threads in this forum with step-by-step info.

-Chap

 

All that is required is the correct fluid and wipe the maf surface clean. Is the one on your car broken? If in on pc. Just clean it. H

 

I suggest you try cleaning the mass air flow sensor using MAF cleaner spray first, before you replace it. Only clean MAF cleaner spray should touch the MAF sensor; do not contact it with anything else.

Use the minimum amount of throttle body cleaner for the throttle body, applied on a clean cloth as previously suggested.

Do not try to use one cleaner for both purposes. The MAF cleaner does not contain residue while the throttle body cleaner contains lubricant.

 

Oh those silly Stealerships !!

I replaced the MAF sensor on my 01 (GEN1) last October for $18, bought off of eBay.

Granted, it's not OEM, but it still functions.

Took all of 10 minutes.

 

Hi Ryan - Roy from Canada trying to help -- I bought a new mass air flow for my 2001 prius for 29.85 plus free shipping. Go to AM-Autoparts.com. Two screws hold it in place. use a stubby philips screwdriver to undo the screws, takes about 10 minutes with the right screwdriver.

 

The mass air flow sensor (Toyota calls it "Meter Sub-ASSY, Intake Air Flow") is used in many different Toyota models and is readily available. I personally would install a used OEM Genuine Toyota rather than buy an aftermarket Chinese clone. Plenty for sale on Ebay, just search for 22204-21010 (which is the Toyota part number). HOWEVER, on Gen1's a dirty throttle body is usually a more common problem than mass air flow sensor so make sure your throttle body is nice and clean.

 

Hi threeprong - Roy from Canada - I agree that an OEM MAF used would be better if still working OK. I have put the chinese new sensors on three 2001 prius cars I own. One needed a new sensor to cure mil light. I have kept the old OEM sensors to use if the chinese one should fail. Used techstream to monitor and they chinese appear to operate identical to OEM ( looking at long and short term fuel trim). The chinese sensors have no markings on them but look physically on the outside idential to OEM. Wonder how they can make them so cheap and still work?

If one of the new chinese sensors fail in the future I will post to warn others.
Since I only paid $500 for each car I find it difficult to pay toyotas high prices for parts, they are only cheap transportation if the cost to maintain them is low.

I would like to thank you threeprong for the connector to the high voltage battery that you sold me, it works well with the highvoltage tester I built. My tester will charge and discharge the high volt battery in the car, if I use techstream I can see the charge and discharge currents and voltages on the 19 battery modules as well as the state of charge on the battery as I am charging and discharging. The connector to nowhere must have its wiring run through the car's current sensors. The techstream is very helpful to bring the battery back to the state of charge it had before the discharge and charge process was started. The car's electronics does not appear to like the SOC to be different.

 

Roy, can you give us any info on the in car tester you built? I like to try and build one myself.
I am really enjoying my lil 01 Prius, now that it has gen 2 battery cells in it. But it would be nice to know how it is doing,
since I did not take the time to balance it.
Thanks
Dave

 

Hi Dave - I can put together a list of parts that I used and a schematic for the wiring. It essentially is a variac with a rectifier, capacitors , contactor and a special connector that I was only able to buy off a person on prius chat that allowed me to plug into the cars battery from the trunk.
I had the contactor in my junk at home, the rest I bought through the internet from various suppliers. Do you have an electrical background or training - my charger puts out up to 350 volts dc at 2 amps and can be dangerous in the wrong hands, from a safety point of view as well as charging and discharging the battery - it is not a fail safe system.

 

Hi Dave - if you want to know how your battery is doing (and not charge and discharge it) buy a mini-vic off the internet and a laptop that runs windows xp. It will run a program tha is called techstream (same as the dealers use). This will allow you to monitor your battery modules for their health. The mini-vic system uses a cable from the car to the computer and comes with a disk that has the software. Many posts on prius chat about this.

Hope this helps

 

Roy, thanks for the info on the Mini VCI cable, its for toyotas, I found them on eBay pretty cheap. I hope its the right one.
I was contemplating making my own charger, with some parts I have laying around, but that might be taking on too much I suppose.
I do have an old IBM Lenovo Thinkpad running Windows XP, it still works fine. Im sure this device would work on other Toyotas as well.
Thank you
Dave

 

Roy,
What is the specifications for the variac? I have seen one a long time ago, But I think it had lower voltages. I have played with power supplies before, for printers, and computers. Can I use a 3:1 transformer, and just hook it up backwards, to step up the voltage, then rectify it, and smooth it out with some caps?
Thanks for your help.
Dave

 

I got one of the aftermarket ones on ebay about 3 months ago and it's worked perfectly, around $20 shipped.