PCV valve snapped. Will permanent P1129 code clear after fix?

[skaughtz]

Quick recap of bad luck. Wife's 2012 Civic LX has 125k on it. Figured I would replace the PCV valve. Took the old off, threaded the new one on by hand, set my torque wrench to spec (32 lbf*ft), gave it a twist, and the S.O.B. PCV valve snapped mid threads.

Not having any way to get the other threads out of the block I called a trusted mechanic two miles down the road who told me to bring it to him. Drove it there with no PCV valev installed, he got the threads out, drove it back no PCV valve installed, threaded the old PCV valve (which still works) back down tight by hand, slapped a wrench on it and tried to give it an easy twist and it didn't move so I called it good enough.

In the meantime, since I drove it to the mechanic and back the emissions system obviously didn't like that. I cleared the temporary codes with my OBDII scanner, drove it again and all of the warning lights remained off (check engine, power steering, VAS system) but the permanent code remains in the computer:

P1129 Honda Permanent
MAP Sensor Signal Higher Than Expected

Will the computer eventually erase this code after driving enough time that it sees the issue doesn't exist anymore, or will I need to take it to the mechanic again to get them to clear it? Maryland emissions only look for these types of codes for pass/fail, so whenever that is due it could be a pain in the butt.

 

[paulo57509]

Since running without a PCV valve is essentially a big vacuum leak, it would affect the MAP sensor in some way. I would venture a guess that the DTC would clear itself after x-number of start/run/shut down cycles.

 

[skaughtz]

Since running without a PCV valve is essentially a big vacuum leak, it would affect the MAP sensor in some way. I would venture a guess that the DTC would clear itself after x-number of start/run/shut down cycles.

Not 5 minutes after I posted this the wife needed to run out for a 15 minute or so drive. I checked it when she got back. The permanent code has cleared, but it is still is showing a yellow light and red (as opposed to green) on the FUE, CAT, EVA, O2S, and EGR (the HTR actually turned green). Whatever the hell those all mean:

I double checked on my Camry and those are all green:

I would hope that it only takes time for the system to reset completely?

 

[zfasts03]

I am guessing not a genuine Honda part?

 

[skaughtz]

I am guessing not a genuine Honda part?

That's the kicker. It 100% was. Straight from the dealership. Correct part number, sealed, and I double checked the torque spec for it through multiple sources. Now, I did get it some time ago (a year or two ago?) and only now remembered about it, but it hasn't been baking in the sun or anything. It should have been A-OK. It was not.

 

[brianl703]

I would hope that it only takes time for the system to reset completely?

When you cleared the codes, you also set all of the readyness monitors to incomplete. That's why they are showing in red.. Not until the vehicle is driven enough to clear them will they complete and turn green.

This is done to prevent someone from trying to get it to pass an OBD-II scanner emissions test by clearing the codes just before the test.

 

[zfasts03]

That's the kicker. It 100% was. Straight from the dealership. Correct part number, sealed, and I double checked the torque spec for it through multiple sources. Now, I did get it some time ago (a year or two ago?) and only now remembered about it, but it hasn't been baking in the sun or anything. It should have been A-OK. It was not.

Now I don't feel so bad about using an aftermarket PCV in my `07 Accord 2.4, that I got from RockAuto, forgot the brand, but so far so good and that was years ago.

 

[skaughtz]

When you cleared the codes, you also set all of the readyness monitors to incomplete. That's why they are showing in red.. Not until the vehicle is driven enough to clear them will they complete and turn green.

This is done to prevent someone from trying to get it to pass an OBD-II scanner emissions test by clearing the codes just before the test.

Makes sense. I appreciate the insight. I will check again in a few days then. In the meantime I have to decide if I attempt to replace the PCV valve again or just let the original one keep doing it job until it doesn't.

I am still rather irritated about the ordeal.

 

[FowVay]

Did you replace the crush washer as specified in the service manual?

The light will reset after 3 consecutive starts with no symptoms detected.

 

[skaughtz]

Now I don't feel so bad about using an aftermarket PCV in my `07 Accord 2.4, that I got from RockAuto, forgot the brand, but so far so good and that was years ago.

It just always seems to be something stupid like this that makes a simple task a headache. Although I wonder if it had anything to do with the engine not being completely cool? Seems like it wouldn't really matter. Anyway, I am going OEM again but I am certainly just going goodentight with the wrench this time.

 

[skaughtz]

Did you replace the crush washer as specified in the service manual?

The light will reset after 3 consecutive starts with no symptoms detected.

View attachment 181934

Yep. 14mm OEM. Same one that goes on the oil drain plug. Thanks for the info. Good to know.

 

[Aredeeem]

No good deed goes unpunished. I’ve learned to wait at least 10 minutes when I get the urge to be pro active. It usually passes.

 

[zzyzzx]

Quick recap of bad luck. Wife's 2012 Civic LX has 125k on it. Figured I would replace the PCV valve. Took the old off, threaded the new one on by hand, set my torque wrench to spec (32 lbf*ft), gave it a twist, and the S.O.B. PCV valve snapped mid threads.

32 ft-lbs for a PCV valve????

 

[The Critic]

32 ft-lbs for a PCV valve????

Those threads look like M14....which should be more than capable of handling 32 ft-lbs. I think the OP needs to get another torque wrench....or revisit his technique.

 

[skaughtz]

32 ft-lbs for a PCV valve????

Yarp. Seemed high to me, too, but I was able to confirm it in multiple places. Here is just one. Page 2 of 5.

https://www.collegehillshonda.com/instructions/civic/2012/4dr/civic_torque_specs.pdf

 

[skaughtz]

Those threads look like M14....which should be more than capable of handling 32 ft-lbs. I think the OP needs to get another torque wrench....or revisit his technique.

So afterwards I started internet sleuthing for information and found that the threads snapping is a more common occurrence than you would like to see with those valves. I replaced it with another OEM valve, but once I got her snugged down by hand I just gave it a goodentight twist to crush the washer a bit and all has been well.

 

[KrisZ]

Not sure what "gave it a twist" means, but if it was a somewhat fast wrench action, then I can see this type of thing happening or the threads stripping. Once the bolt threads all the way in by hand and there is resistance on the threads, the final torquing action should be done slowly.

I think OP simply went too fast.

 

[skaughtz]

Not sure what "gave it a twist" means, but if it was a somewhat fast wrench action, then I can see this type of thing happening or the threads stripping. Once the bolt threads all the way in by hand and there is resistance on the threads, the final torquing action should be done slowly.

I think OP simply went too fast.

It isn't rocket surgery and I don't play fast and carefree with my multi-thousand dollar investments. Mid-way through torquing it down it snapped because Murphy's Law. It's all good now, but apparently it is not uncommon with this PCV valve, which is something I did not know at the time of this post.

 

[The Critic]

It isn't rocket surgery and I don't play fast and carefree with my multi-thousand dollar investments. Mid-way through torquing it down it snapped because Murphy's Law. It's all good now, but apparently it is not uncommon with this PCV valve, which is something I did not know at the time of this post.

I’ll just say that torque wrenches can be very sensitive to how they are used. If you flex the head a bit too much, their measurement of torque can be inaccurate…especially on the lower end of their range.

 

[zzyzzx]

I would not use a torque wrench on a PCV valve. In fact, I've never encountered one that didn't just push into a gromet.