MAF Sensors
 

My car randomly goes into limp mode when starting her up (I’ll shut her off and open the driver door and this always takes out of limp mode) and I get the MAF sensor code on the obd 2 scanner.

I was able to get around cleaning both MAF sensors tonight. For the two screws per sensor, I noticed they had to be “broken” off loose (they made a snapping sound right before being able to turn them loose). When putting them back on, do they have to be tightened to a certain point? Or as long as it’s on there good, should it be okay? I’m asking because I didn’t notice any gaskets and didn’t want to experience a vacuum leak. I def. won’t be using a Philips head driver in the future, as the metal seemed soft and borderline stripped the top of the screws.

There is some stiction between the metal screws and the plastic housing which causes the pop when you break them loose - it's normal. There should be torque specs in the FSM but I just got mine "hand-snug" and called it good.

The FSM says the screws for the MAF sensor should be torqued to 1.47 Nm or 13 in-lbs. That is extremely light, so its easy to overtorque.

Two of my favorite members of this forum. Thank you both! :tiphat:

Also, if I over-torque the screws, any consequences? Can’t imagine getting the system getting a false read from this lol

You're liable to break something. Make sure the MAF flange is square with the duct flange and snug up the screws. If you don't have a torque wrench, you can rent/borrow one at most auto parts stores. Once you've done it with a torque wrench, you should be able to get close enough by hand.

For those low torque settings a Fat Wrench works great.

https://www.wheelertools.com/gunsmit...iAAEgKNzfD_BwE

So the paranoia got the best of me, and went to unscrew the bolts and lightly tightened by hand with a Philips head, almost to where I could probably unscrew by hand if I tried really hard.

Took her for a spin since I had the garage door open. On a side note, the can stated cleaning would result in a 4-10 hp gain at the wheels, which I find hard to believe. Someone on a youtube vlog, who also stated they were registered on this forum, also said their car felt faster. Perhaps cleaning the MAF sensors gives you the original power back from when it was first built, and not an actual power gain?

You got back on what you lost. You didn't gain any.

What was the exact code?

I don’t recall the exact P code, but I do remember it saying “MAF sensor” at the bottom of the scanner.

Even after cleaning both MAFs, car still goes into limp mode, which leads me to believe I will need to clean the TBs.

Just be careful cleaning them.


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I am actually really hesitant/nervous about doing it. I read that it's not part of the recommended maintenance item, and done extensive research about it on both this forum and the G37 forum, and seeing mixed information/stories about cleaning them.

I'm reading from some people are disconnecting the battery, while others don't and that disconnecting will require the relearn procedure; to the relearn procedure not being necessary; to moving the butterfly will mess up the ECU's calibration; to replace/not replace the o-ring, to leaving the TB on/take then off when cleaning, etc.

I've seen youtube videos and seems like a straightforward process, but the differing/contradictory information is what's stopping me.

Don't worry about all that. Just disconnect the negative battery terminal if you're at all concerned. I've done it on a bunch of 370Z TBs all different ways: with and without the battery connected, with and without removing TBs (o-rings looked good and didn't need replacement) and always lots of butterfly valve movement to get the back side clean, especially if you leave them installed. Never had an issue other than needing to relearn the accelerator pedal position, which is super easy.

Liberal use of the right cleaning products (MAF cleaner and Throttle Body cleaner) will be just fine. Use a stiff bristle brush to aid in the cleaning process (only on the TBs, not on the MAFs).

I cleaned my MAFs several times and it was VERY easy - if you can use a screwdriver and a spray can, you can do it. The MAFs are not particularly fragile - they can stand up to the environment under the hood - but you don't want to bang then around. Do not poke the cleaner straw into the MAF body; there is a thin wire that you could break if you make contact with it.

According to what I've read on this site, cleaning the TBs is a more complicated job but still pretty easy (see JARblue's comment above). There are several threads explaining the procedure.

As usual, good info from jarblue and southark370z!

Cleaning the MAFs was really simple. I actually sprayed down and waited about an hour to ensure it was fully dried.

I will be moving forward with the cleaning of the TBs, just a matter of finding time.