Yet another thread on P2177 and P2187

Gen 1, mods in my signature below. 160k Miles and all of them are mine (I bought this car new with 60 miles on it). Runs great, no misfires, smooth even idle but I get the occasional 2177 or 2187 but never at the same time, though.

Lately (last 10k miles or so) those 2 codes are getting more common. I used to see one every 1-6k miles but now I am getting one of them about every tank, maybe 2 per tank. I get them about the same whether I run my E33 or 91 octane tunes (both are from Justin at Freaktunes). Plugs (NGK Iridium) look good and have about 30k miles on them. When I plug in my AP and watch AFR, it cycles when I blip the throttle so I am assuming my wideband O2 is good. Fuel pressure looks normal to me (usually around 1500+ when cruising and about 500 when idling) but I am no expert. I inspected all my boost tubes and vacuum lines, they look good.

I took a log but I did not have a CEL before, during, or after the log so I am not sure it will show anything but can post it anyone wants to see it.

Where should I go from here? both O2 sensors are original. Should I suspect one of them?

 

Year/Make/Model: 2009 MS3 Genwon
Mileage: 160K
Location: Boise ID
Concern: See above
DTC's: 2177 Engine lean at idle 2187 Engine lean off idle
Modifications: See signature
ECU/Tuning Software: Factory ECU, AP V3
Tuner: Justin @ Freaktune
Is the concern intermittent?: Yes
Can you duplicate the concern?: sort of. drive it long enough and it comes back
Recent Repairs: None. Re-gapped my plugs 2k miles ago but no changes before or after
Correction: N/A at this point

 

sounds like you have a leak, try a boost leak test and also inspect your maf o ring

 

Will do both this week! Heading to HD to get boose leak tester parts TODAY!

 

Last night I bought all the parts to make my boost leak tester. Will assemble it tonight but won't be able to test it for about 10 more days (on a bidness trip, then camping).

I pulled my MAF to check the O-Ring. The o-ring looked fine but when I was putting it back together, my MAF does not sit flat. Look at the difference between the two mounting points. I could rock it with my fingers on the high spot.
gdurl.com/8UcW
When I get home I will file it down. for now I just wrenched the screws a little more and that seems to have got it to sit level.

On my way to work today, I watched both Long and short FT. They are all over the place. I am looking forward to checking for leaks!

 

Got home and hooked up my boost leak tester. I could hear more than a hiss coming from around the turbo inlet. When I put my hand on the turbo inlet, I could change the sound of the hiss by moving the turbo inlet. So I pulled it off.

I found the clamp that held the turbo-inlet-to-turbo coupler was slightly cocked on the turbo inlet side. So I cleaned everything up and put it back together but this time spent a few mins verifying all the clamps were square. When I was done, I hooked up the boost leak tester again and the hiss was gone and my intake tract seems to hold 20PSI.

I put the whole car back together and have about 30 miles on it since; so far no CEL. My LTFT and STFT are still a bit out of whack (usually hovering about 10 to 25 combined) but they are not jumping around like they were before I adjusted that coupler/clamp. I am not going to call it "fixed" unless I get through 2 or 3 tanks of gas without a CEL but I am hoping that was it. I also don’t want to really dig into my intake track looking for any more leaks until my truck is on the road (probably about 2 more months). I guess it will be time to clean my intake valves again then, anyway.

 

glad it seems to be fixed, hopefully that did it