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Discussion Starter #1
P0104, if you try to reset it, it comes back on within 5 seconds. (Perhaps a pending code keeping it on?)

Read up on the code and did the following:
-Verified that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.
-Inspected for any air leaks near the MAF sensor.
- Tried MAF Sensor cleaner.
- Tested old MAF Sensor with Ohmmeter.
-Replaced the MAF sensor.
The light still stays on and I'm running out of time to get it fixed before I have to do the yearly emissions test in which they fail you if you have any CELs.

The balt' still runs great, but I have noticed a little less gas mileage driving 500 miles a week.

Any thoughts/tips.

I don't mind keeping my car free of CELs, but I feel emissions testing that forces me is a little overkill.

Nonetheless and rants to the side, I could use some brain power on this now that I'm already $50 in and still have a CEL even after testing.
 

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Did you check the connection at the ECM? The MAF wires go directly to one of the ECM connectors. Remove spray clean and re-install. Disconnect battery first.
 

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Discussion Starter #3
removed both ECM connectors, cleaned and re-installed after disconnecting battery, no luck.

Thanks for the idea though, hadn't thought of that, any others?
 

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Yeah try what cost nothing first, sorry it didn't work for you.

You will need to trace wires, check an make sure intake hasn't seperated from throttle body.
 

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Discussion Starter #5
- Double checked to make sure, intake has not seperated from throttle body, did let me know that my throttle body hasn't been cleaned in a while and what 20k miles can do, lol.
 

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So no air leaks hummm!!! What about crankcase ventilation tube or where it hooks up to on the intake.
 

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Discussion Starter #7
Checked that when I toke it off and made sure it was leak free when I put it back on.

Its an odd one.
 

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:confused:Mass air flow is obviously working because you would get a different code than P0104. This code is telling us that the amount of air going by the mass air flow sensor doesn't match the other means of measuring like the "MAP" and amount of fuel. So it either has to be a leak or an obstruction like a very dirty air filter, but this would bring down your mpg and should give you codes other than P0104. Was your throttle body on tight? Did you ever remove your throttle body, was the gasket in good condition? Do you hear a hissing sound while engine is running?
 

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Discussion Starter #9
I have noticed a very slight drop in mpg, but i've also been running a 3k rpm shift point instead of 2.5k, Throttle body was on tight, I haven't removed the throttle body in a year and I didn't take it off fully when I was just cleaning it after I got the car and the gasket was in good condition. I do not hear any hissing sound unless it's a very small one but I've tried to rule out as much as possible.
 

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This is a long shot but since leaves have started to fall maybe your inlet box picked up some leaves or like one member on here had a beehive under the filter. I see you removed the first part of the inlet.
 

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Discussion Starter #11
I'll have to check, it's only been 2-3 months since I replaced the air filter, but that is a possibility.
 

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The member with the beehive had replaced his 2 weeks prior to his incident, was he ever surprised to find the honeycombs stuck to his filter. Also had a member with a squirrel nest. Filter was OK but inlet was plugged with debris.
 

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Discussion Starter #13
I gotta admit if that was the fix i'd kick myself a bit, but I wouldn't mind, but sadly I just checked and there isnt anything in the inlet and the box itself just had a light layer of dust.
Filter is pretty clean.
 

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Yeah, well I'm running out of ideas, aside from being there with the tech2 in hand it's pretty hard from here
 

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Discussion Starter #15
Hm,

I might be able to bum a tech2 off of one of my uncles,

Worst case scenario, the dealer I bought it from is willing to look at it and possibly fix it, but they're in a questionable area and each time I get it back it it's on E.
 

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Your MAF is working, inlet is sealed, filter isn't clogged but for some reason your ECU is not receiving a MAF sensor value that it expects as if a voltage is low. I wonder if the tabs of the ignition 1 voltage fuse might have started to corrode offering a bit of resistance and lowering reference voltage to the MAF and other sensors. Did you check if the "MAF" had the 11 volts regulated reference voltage?
 

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Discussion Starter #19
looks like B is ground and C should be the positive when I hook up my Multimeter correct?
 

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MAF has to be plugged in though and yes your right.

But I'm a bit puzzled because while reading up on code P0104 I comeup with it as an invalid code for a 2007 Cobalt. So why are you getting a P0104? Are you sure it was P0104 because there is a P0103 and P0106?

---------- Post added at 11:48 PM ---------- Previous post was at 11:44 PM ----------

Can't find it in the service manual did a search.
Only found ;

Ignition 1 Voltage
P0030, P0036, P0102, P0443
P0101
P0102
P0103

MAF Sensor Signal

P0102
P0101, P0103, P1101
 
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