MAF Sensor-Stripped Heads

[dl122525]

Hello,

I've seen a lot of old threads about cleaning the MAF Sensor but nothing addressing the problem I have now.

I have 2001, 3rd Generation and the heads of the screws holding in my MAF sensor are stripped out. T

They are recessed so cant really get to the heads. They are so tiny that finding a screw extractor might be difficult but even if I do, getting to it at the angle it's at would prove difficult, if not impossible to get to with a cordless drill to drill out these tiny screw heads to get the extractors into them to pull them out.

Has this happened to anyone else? If so, any other ideas are appreciated.

I could get mad and just chip the MAF into pieces and get to the screws....kinda defeats the purpose though, right?

I have very basic skills...I'm not a mechanic, so please be gentle.

David

 

[Rock_Rat]

If you weren't certain you could do it with the Air Filter Box installed, you should have removed it. You know what they say about spilt milk...anyway...

Disconnect your ISR from your Air Filter Box and remove your Air Box (three bolts).

Then you'll have the access you need to remove the screws with either a drill or a screw extractor. Even a seasoned mechanic would have a tough time removing those screws with the box installed.

Here's a photo of the air box removed. Air Box

NOTE: ENSURE THERE'S NOTHING IN THE BOX BUT A FILTER AFTER YOU INSTALL. VACUUM AND USE A CAN OF COMPRESSED AIR TO CLEAN ALL THE SWARF AND OTHER STUFF OUT!

 

[99Runnr]

Got a dremel? Cut a slot into the head and use a flathead to turn it out.

Or left handed drill bit very slowly can grab it and loosen it.

Drill bit GENTLY until the head of the screw pops off then grab the threads with pliers once MAF is removed.

Gentle tap with a flathead to try and jar the screw loose going counter clockwise. Just don't hit the MAF lol.

Burn it with fire and get a new one.

 

[Rock_Rat]

You must have missed the following in my thread:

Steps

• "If you feel you don't have the proper leverage, then I recommend you remove the air box so you don't strip the screws."
  
  See post: MAF Sensor Removal
  

Just take your time, don't rush and you can do it. No need to destroy your MAF Sensor.

 

[Rock_Rat]

Got a dremel? Cut a slot into the head and use a flathead to turn it out.

Or left handed drill bit very slowly can grab it and loosen it.

Drill bit GENTLY until the head of the screw pops off then grab the threads with pliers once MAF is removed.

Gentle tap with a flathead to try and jar the screw loose going counter clockwise. Just don't hit the MAF lol.

Burn it with fire and get a new one.

The box still needs to come out

 

[s20004runner]

You must have missed the following in my thread:

Steps

• "If you feel you don't have the proper leverage, then I recommend you remove the air box so you don't strip the screws."
  
  See post: MAF Sensor Removal

happend to me, luckily I got it out before it stripped completely. Soaked it in penetrating oil then I had removed the entire airbox to put more pressure on it. I promptly replaced it w/ hex head bolts from a hardware store. Other than an extractor, don't have any advice. Good luck.

IAC on the throttle body has similar bolts so if you ever decide to clean it, be careful.

 

[99Runnr]

The box still needs to come out

Roger, I read the portion assuming he did that and couldn't access the recessed screws. The air box is what, 3 bolts and a hose clamp to remove that section? It's cake, as mentioned just watch out for the debris in there.

 

[dl122525]

Yeah,a friend of mine suggested removing the airbox right after I posted this. That's what I'll do..Thanks for the replies!

David

 

[Humble Leader]

for those of you that replaced the MAF screws with hex head screws what screws did you use. I'm going to replace my screws as a preventative measure next time I've got the hood open but can't seem to find the right ones. I tried what I thought was M4 0.7 pitch but it didn't thread. M3 was too small. M5 will be too big. what the heck. I have a 2012 with the pan tapping screws that have what appears to be a higher pitch than 0.7. everything online says m4 0.7 10mm though but maybe that's for the newer 5th gens :wtf:

edit: sorry I didn't realize this was the 3rd gen forum!

 

[spartacus]

for those of you that replaced the MAF screws with hex head screws what screws did you use. I'm going to replace my screws as a preventative measure next time I've got the hood open but can't seem to find the right ones. I tried what I thought was M4 0.7 pitch but it didn't thread. M3 was too small. M5 will be too big. what the heck. I have a 2012 with the pan tapping screws that have what appears to be a higher pitch than 0.7. everything online says m4 0.7 10mm though but maybe that's for the newer 5th gens :wtf:

edit: sorry I didn't realize this was the 3rd gen forum!

It should be m4 x0.75 x10mm.

 

[Ghostrider]

I posted this a few times so searching should find. I don't have the part number handy but the posts have a part number from either Lowes or HD. That number is for the hex screws to replace the horrible cheap crap Toyota put in. They saved a few pennies versus just doing it right.

 

[davidch]

As to 4mm thread: it's my understanding that normal 4mm metric thread since the late 1960s is 4x0.7.

This thread chart shows that, as do others:

ISO 724 - Metric Threads

This chart shows a 4.5mm thread that does feature 0.75 pitch.

ISO Metric Thread | Metric Thread Chart | Apollo International

There exists a JIS (Japanese Industrial Standard) that vehicles - cars and motorcycles and what not - used in the 1960s. Japanese motorcycles and cars starting in about 1967 began using ISO threading. There was usually a sticker affixed somewhere on the bike that told of this.

Here's a site that explains the changes, with ISO and JIS charts:

Early JIS Threads - Classic Fasteners

I have seen, recently in an ACE hardware store, taps and dies in M5x0.9. Why?

There may be some M4x0.75 taps and dies out there as well. I don't think they'd be of much use, unless you're working on a Honda CB77 or a Datsun 1600.

 

[Humble Leader]

It should be m4 x0.75 x10mm.

I thought maybe, but the 0.75 won't be coarse enough. this reddit thread isn't mine but someone posted about losing their screw from their 4th gen and it's the exact screw that I have

Dropped one of my 4th gen MAF sensor screws and it went into another dimension. Anyone know what size this is and where to get one? : 4Runner

the part number is Air Mass Sensor Bolt - Toyota (90167-A0016) however it doesn't say it fits 5th gen 4runners. I'm sure it does because it does fit the FJ and a couple other parts sites say it does fit the 5th gen

As to 4mm thread: it's my understanding that normal 4mm metric thread since the late 1960s is 4x0.7.

This thread chart shows that, as do others:

ISO 724 - Metric Threads

This chart shows a 4.5mm thread that does feature 0.75 pitch.

ISO Metric Thread | Metric Thread Chart | Apollo International

There exists a JIS (Japanese Industrial Standard) that vehicles - cars and motorcycles and what not - used in the 1960s. Japanese motorcycles and cars starting in about 1967 began using ISO threading. There was usually a sticker affixed somewhere on the bike that told of this.

Here's a site that explains the changes, with ISO and JIS charts:

Early JIS Threads - Classic Fasteners

I have seen, recently in an ACE hardware store, taps and dies in M5x0.9. Why?

There may be some M4x0.75 taps and dies out there as well. I don't think they'd be of much use, unless you're working on a Honda CB77 or a Datsun 1600.

where did you see the m4.5 that has a 0.75 pitch? I don't want to use a tap or anything like that to make a screw fit. I thought I'd be able to do a simple replacement of the screws but I was wrong. everyone was saying they used m4 0.7 but there's no way that is fitting on my 4runner. however that same bolt is used on the TRD CAI. maybe earlier

 

[spartacus]

I thought maybe, but the 0.75 won't be coarse enough. this reddit thread isn't mine but someone posted about losing their screw from their 4th gen and it's the exact screw that I have

Dropped one of my 4th gen MAF sensor screws and it went into another dimension. Anyone know what size this is and where to get one? : 4Runner

the part number is Air Mass Sensor Bolt - Toyota (90167-A0016) however it doesn't say it fits 5th gen 4runners. I'm sure it does because it does fit the FJ and a couple other parts sites say it does fit the 5th gen




where did you see the m4.5 that has a 0.75 pitch? I don't want to use a tap or anything like that to make a screw fit. I thought I'd be able to do a simple replacement of the screws but I was wrong. everyone was saying they used m4 0.7 but there's no way that is fitting on my 4runner. however that same bolt is used on the TRD CAI. maybe earlier

Just order it from the dealer 90167-A0016 or take one off and compare it at the hardware store.

 

[Humble Leader]

Just order it from the dealer 90167-A0016 or take one off and compare it at the hardware store.

Ya I think that's what I will do. there are part shortages up here where I am, I'd be lucky if any dealers actually have these screws

Already checked locally in my (small) city for a match at hardware stores. we don't have much metric selection up here, especially in the small sizes. after three different stores I said f-it and asked on here. probably worth investing in a $20 bolt/screw gauge. I have to get most of my metric bolts/ fasteners from amazon. it would make life so much easier to be able to walk into home depot, match a screw and be on my way!

 

[octanejunkie]

I just went to Ace Hardware and matched one of the screws with a hex cap screw

 

[busmup808]

Wow this literally happened to me last night to one of the bolts. I drilled the head out in increments till the head almost fell off. Pulled off the maf after the head came off. I thought the threaded stud was going to be stuck, but it was loose and I screwed it off by hand. I had another bolt on my extra bolts container. I cleaned the maf and connected it back together with the two bolts. My truck is a 98 and I’m installing a 02 maf with intentions to install my blower soon.


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[Humble Leader]

update: finally got the screws in last week. took 3 weeks. they are about 11mm long, m4 and 1.0 pitch. measured using a gauge, and fit perfectly. hopefully this helps someone else. I have a 2012 for reference