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p0172 CEL pending, rough idle, stall at idle.

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Old 05-12-2012, 02:55 AM
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Question p0172 CEL pending, rough idle, stall at idle.

Ok... details first. I have a 2012 tc. bought it with 16 miles on it, now it has about 6k. The only performance mods I have are a tsudo cat-back and an AEM intake. The exhaust has been on for a couple of weeks... the intake a month and half. Up till today, I havent had a single problem.

I was at a red light tonight and all of a sudden... all the warning lights came on and the car stalled. Started right back up. I used my scan tool to see if there was an active CEL, all I saw was a p0172 PENDING( bank 1 too rich). It never showed as an actual fault code. Only pending.

I have an app that runs with a bluetooth adapter. When driving fast or slow.... feathering gas pedal or flooring it.... long drive or 1 block it says the AFR is 14.7:1(average). When I sit at a light, idle or parked for more than 2 minutes, the car begins to idle really low rpm... the car, i assume, tries to correct... revs high... idles fine for a few seconds and then drops again... after the 3rd time it stalls. During this time, the app says it has an AFR of 11.5:1 or so.

The only thing that was out of the ordinary is yesterday we had A LOT of rain, and I went through several puddles... I wouldve imagined that water logging wouldve been more catastrophic.... but my imagination has a way of getting away with me.

Any suggestions would be very welcome.
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Old 05-12-2012, 03:32 AM
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If you have a cold air intake, I would avoid puddles in the future. Check and see how dirty your filter is. If your filter is really dirty, your MAF sensor probably is too. Dirty MAFs can cause this code.
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Old 05-12-2012, 04:30 AM
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I was having that same problem while also getting p0101 (Mass Air Flow (MAF) Circuit Range/Performance Problem.) Took of my intake and found that the rubber coupling had a rip in it (been on car for almost 2 years). I reinstalled my oem intake and have no problem with many highway runs and quick start and stops. I bought a new coupling today and will install with my cai and see if that was the problem. So I would go over all the rubber fittings and the MAF fitting to make sure there tight and no rips/holes.
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Old 05-12-2012, 06:31 AM
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the good thing is that you are still in warranty. if i were you, i would throw your stock intake back on and see if you are getting the code still. if you are, take it in to the dealership and request they fix it.
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Old 05-12-2012, 03:55 PM
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I got that also after going through a puddle(I have a cold air intake also). After driving it for a couple days though, the code is gone and I have had no problems with it and no cel.
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Old 07-28-2012, 08:00 PM
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Originally Posted by DragonR
Ok... details first. I have a 2012 tc. bought it with 16 miles on it, now it has about 6k. The only performance mods I have are a tsudo cat-back and an AEM intake. The exhaust has been on for a couple of weeks... the intake a month and half. Up till today, I havent had a single problem.

I was at a red light tonight and all of a sudden... all the warning lights came on and the car stalled. Started right back up. I used my scan tool to see if there was an active CEL, all I saw was a p0172 PENDING( bank 1 too rich). It never showed as an actual fault code. Only pending.

I have an app that runs with a bluetooth adapter. When driving fast or slow.... feathering gas pedal or flooring it.... long drive or 1 block it says the AFR is 14.7:1(average). When I sit at a light, idle or parked for more than 2 minutes, the car begins to idle really low rpm... the car, i assume, tries to correct... revs high... idles fine for a few seconds and then drops again... after the 3rd time it stalls. During this time, the app says it has an AFR of 11.5:1 or so.

The only thing that was out of the ordinary is yesterday we had A LOT of rain, and I went through several puddles... I wouldve imagined that water logging wouldve been more catastrophic.... but my imagination has a way of getting away with me.

Any suggestions would be very welcome.
I have a 2008XD and just installed AEM Cold intake and Strupp Exhaust about 1 month ago, has run perfect until yesterday with same exact symptoms as DragonR described above, have same code P0172, someone suggested cleaning MAF, what should I use to clean it with? Any other suggestions? Thanks Steve
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Old 07-29-2012, 04:16 PM
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i had the same issue it might be the electronic tuner box on the aem. i unplug mine and reset the ecu and im good now.
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Old 07-29-2012, 04:25 PM
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There is specific maf cleaner they sell at auto parts stores. Using the search thread will probably come up with it. Can't remember the brand I bought. Red/black can I think

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Old 07-29-2012, 08:01 PM
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MAF sensor cleaner, as stated above. any auto parts store sells it. It's cheap too. Disconnect the battery's neg. cable first. Then follow the directions on the can, and do not touch the element on the sensor with your hands what so ever. Reconnect the battery after you re install everything. Start the car and allow it to idle for a while. The ECU will have to relearn air/fuel ratios and your driving habits.. Give it some time..Sounds like you guys might have sucked in some water, it will dry out in a few days. If that does not work, warranty.. Good luck with the Service dept. You'll need it.
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Old 08-01-2012, 06:22 PM
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Cleaned MAF sensor with cleaner, reinstalled, reset ECU, has been running good so far, hope that was the fix
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Old 09-02-2012, 05:31 PM
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I used a crc brand maf cleaner, supposedly the best on the market. Same problem. I put in a new maf sensor. Same problem. I found out it was the piggy back maf sensor that comes with the aem intake I installed.
I bypassed that little box, reset the ecu..... haven't had an issue since.

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