CEL - master flow sensor - caused by cold weather?!

[YepYep]

Recently I got me CEL again, after I parked my car outside for one night...

Then it just on and off from time to time for about one week or 2 already.

I had it scanned and found only one code (I forgot...), and it's about the air intake master flow sensor.

I did use a short ram intake before but changed back to the stock box with a KnN filter only for a long time.

And the on-n-off CEL, I found something insteresting, looks the cold temperatures under the hood will turns it on. And a warmer temperature will do good to it. E.g. after clear the code with the scanner, if I keep using the car, the CEL will not turn on again. But after I park the car for enough long time to get the car cold down completely, the light will turn on... We got some days a little bit warmer, the light will also have a chance to turn off by itself...

Any idea about it? Thanks so much for your input in advance!!

I asked the price for replacing the flow sensor, it costed! Original OEM will be above 200, or Denzo brand for about 180... If I do need a new sensor, I want to confirm if paying this money is a must do....

[YepYep]

Nobody has any ideas or similar experience??
Today we have a higher -3 temperature, and when I left office for lunch, the CEL just gone....
Don't know when it will come back again as we still have a long winter here...right?

[McGuyver_3]

First off, your english is some what complicated to understand but I am going to try and help anyways.
What kind of Mass air flow sensor fault do you have? Lean, rich or a p0100code If i remember correctly. Does anything like that sound familiar?
If you had a short ram, your wires could have stretched causing intermitant connections and you will need wiring repair. Or your sensor could be bad. The last time I priced out a sensor at the dealer for a regular mazda 3 it was in the 80-90$ range The Speed3 sensors are pricey though.
This is simply a guidline, there is much information on this forum about wires stretching due to short rams and MAF faults. Without a proper code you are better off having it diagnosed in order to prevent paying through the behind for guesses

[kickz]

whats the code you got ?
possible the wires at the maf are loose pretty common

[Lmmorden]

whats the code you got ?
possible the wires at the maf are loose pretty common

Yep... Fixed peterm15's the other day.. Was running like crud

Edit: pretty easy to diagnose with a voltmeter

[coppermica]

i had some cel light issues a few months ago . thought it was broken wires or loose connection .i even replaced the maf sensor its self . it turns out the software on the cars computer was out of date and that wasn't something i could fix myself . so if ur not a very good mechanic and everything looks normal take it in to a professional they can atleast tell you what the problem is. 200 seems a bit high for oem maf i paid 100 from mazda.

[azdame]

Had a MAF sensor code pop up early this winter (late November) when we had the first huge freezing drop in temperature. Reset it, it hasn't come back.

[geobur]

I am having this exact same problem, it is on and off. It will come on for a day or two then disappear.

I don't want to buy the expensive sensor if that isn't what's wrong. Had Jimmy do an oil change on it last week and he looked at the sensor and said it seemed to be plugged in ok. I didn't start getting this problem till this year with some cold weather. It actually popped up around the same time I got my first car wash in the winter.

[Lmmorden]

I am having this exact same problem, it is on and off. It will come on for a day or two then disappear.

I don't want to buy the expensive sensor if that isn't what's wrong. Had Jimmy do an oil change on it last week and he looked at the sensor and said it seemed to be plugged in ok. I didn't start getting this problem till this year with some cold weather. It actually popped up around the same time I got my first car wash in the winter.

Loose maf pin me thinks... Grab a multimeter and start testing those pins

[geobur]

No idea where to find the sensor, and i don't own a multimeter lol. Nor do I know what voltage should be going through it's

[coppermica]

the are video's on youtube that show you how to check maf with a multimeter and what voltage you should see.

[YepYep]

Yes... The MAF sensor is just 100 from dealer. I checked the price this morning, when buying the air filter.

I have the light gone after I replaced a new stock air filter.

So maybe you guys could like to check the air filter first, maybe go replace it directly for less than 40 from dealer.

I was going to place the stock filter and then have the KnN filter to be cleaned and re-oiled and see. But now, as the light is gone, I think I may put the KnN back in the box after cleaning for some time and wait and see...

I was told the air sensor value was programmed more strictly in Mazda cars than other brands... Looks it's true....

[Lmmorden]

No idea where to find the sensor, and i don't own a multimeter lol. Nor do I know what voltage should be going through it's

I can help!

[geobur]

I can help!

That would be awesome! Install day?

[Lmmorden]

That would be awesome! Install day?

If it happens.. You can stop in when we are doing my shocks

[geobur]

If it happens.. You can stop in when we are doing my shocks

When are you doing your shocks?

[Lmmorden]

My place or peterm15's house @geobur

[geobur]

My place or peterm15's house @geobur

lol I figured that, but when?

[Lmmorden]

When my shocks get delivered.. Lol @geobur

[mustu521]

Sorry to revive an old thread but this is so ironic. I've got the same exact issue. The CEL going on on cold winter days (specially after parking the car outside on a cold night). I read the codes for the CEL and it turns out to be P0101 which is a MAF sensor circuit range/performance problem. Hoping to clean out the MAF and check. I have a Mazda 5 2008 (2.3L same engine as the 3, all stock). Anyone faced this issue with their 3's or 5's ?

[G ~ MINI]

I've had my MAP sensor trigger a CEL for several months before i replaced it ...mostly always happened when very damp / condensation ... replaced

[dbear]

Sorry to revive an old thread but this is so ironic. I've got the same exact issue. The CEL going on on cold winter days (specially after parking the car outside on a cold night). I read the codes for the CEL and it turns out to be P0101 which is a MAF sensor circuit range/performance problem. Hoping to clean out the MAF and check. I have a Mazda 5 2008 (2.3L same engine as the 3, all stock). Anyone faced this issue with their 3's or 5's ?

Reviving this Thread 1 year later... Also had my Engine Light come on a bunch of times in the last couple of months. It comes and goes but when driving it feels just fine. I took my M3 (2011) to my mechanic and he said it was the Mass air flow sensor and that he could replace it but it wouldn't guarantee the fix. He checked everything else, said it was fine and to leave it until it stalls or whatever....coming from his experience. I felt a little uneasy so I bought a OBD reader to see for myself. Code turns out to be P0101 as well. After browsing through this thread, somebody mentioned to clean the engine filter and it seemed to work as its been 6 days now and the Engine light hasn't come on. I'm gonna plug in the OBD reader later and see if it still picks up any codes even if its off. Anyway, I had one of those K&N filters where I took it out, washed with the provided spray, let dry and re-oiled it. Hopefully no more problems as it continues to drive perfectly fine.

[G ~ MINI]

Quite possible the K&N wasnt totally dried and triggered it...

I also had the intake to airbox fill with ice pellets on a winter drive to MTL and it CEL came on.