SOLVED: spark plug change - now getting lambda adaption codes

[hackR]

my car is a '09 e92 m3 with 84k miles...has the Alex Alpine tune...

i removed the air box, plenum and replaced the spark plugs with NGKs...believe i seated all the ignition coils properly...everything went back together fine...but now i am getting the "increased emissions" message along with the check engine icon...pulled the codes and can't seem to find any explanation...

1) 27AA Lambda adaption at VKAT stop bank 1
2) 27AB Lambda adaption at VKAT stop bank 2

reading various posts, i've seen possible causes of
a) replace o2 sensors pre-cat
b) check/replace intake manifold pressure sensor (map sensor)
c) check induction system B1 for leaks (i have no idea what this means?)

i have cleared the code a couple times, but it comes back...the car runs great...have also read that sometimes codes come/go and this might happen...it's only been a couple days so not sure if i should just drive it and see if it goes away...also not sure how the overall car adaptions fit into this...

pondering taking it all apart and re-doing it...could it possibly be a) the seating of the ignition coils?, b) the seating of the plenum on each throttle body?

any assistance would be appreciated...i am finding it odd that it would be a bad sensor so thinking its related to plenum, airbox or ignition coil seating, etc...

thx...R

[Bubbles]

Originally Posted by hackR

my car is a '09 e92 m3 with 84k miles...has the Alex Alpine tune...

i removed the air box, plenum and replaced the spark plugs with NGKs...believe i seated all the ignition coils properly...everything went back together fine...but now i am getting the "increased emissions" message along with the check engine icon...pulled the codes and can't seem to find any explanation...

1) 27AA Lambda adaption at VKAT stop bank 1
2) 27AB Lambda adaption at VKAT stop bank 2

reading various posts, i've seen possible causes of
a) replace o2 sensors pre-cat
b) check/replace intake manifold pressure sensor (map sensor)
c) check induction system B1 for leaks (i have no idea what this means?)

i have cleared the code a couple times, but it comes back...the car runs great...have also read that sometimes codes come/go and this might happen...it's only been a couple days so not sure if i should just drive it and see if it goes away...also not sure how the overall car adaptions fit into this...

pondering taking it all apart and re-doing it...could it possibly be a) the seating of the ignition coils?, b) the seating of the plenum on each throttle body?

any assistance would be appreciated...i am finding it odd that it would be a bad sensor so thinking its related to plenum, airbox or ignition coil seating, etc...

thx...R

Check everything you unplugged to replace the plugs and ensure the plenum is seated correctly in the rear.

[hackR]

Originally Posted by Bubbles

Check everything you unplugged to replace the plugs and ensure the plenum is seated correctly in the rear.

Is there a trick/tip to seating the rear?...

I re-installed the plenum a second time and started rear to front...pushing down evenly...any advice?

[hackR]

argh...so i figured this out after quite a few - quite a few! - removals/installations of the plenum...

when i removed the plenum the first time, i loosened the 8 clamps holding the plenum to the throttles and pulled it up...it came off easily with a pop...

when re-seating/re-installing the plenum, i finally realized that the clamps needed to be opened more - especially the back ones...once i did that, the plenum fit perfectly...

a tip - shine an led flashlight down each bank to see that the plenum fits all cylinders evenly...its easy to see the fit when you shine down each bank from the front to the back...

the codes - btw - indicated that the air/fuel ratio was not right due to the misaligned plenum...

all good now!

[nsogiba]

Too loose, and the clamp can move around too much and not be seated in the groove of the boot when tightened.

Too tight, and the boot lip will grab the base of the velocity stack shoulder, rolling it over and causing a leak.

Nice catch!

[Bubbles]

Originally Posted by hackR

argh...so i figured this out after quite a few - quite a few! - removals/installations of the plenum...

when i removed the plenum the first time, i loosened the 8 clamps holding the plenum to the throttles and pulled it up...it came off easily with a pop...

when re-seating/re-installing the plenum, i finally realized that the clamps needed to be opened more - especially the back ones...once i did that, the plenum fit perfectly...

a tip - shine an led flashlight down each bank to see that the plenum fits all cylinders evenly...its easy to see the fit when you shine down each bank from the front to the back...

the codes - btw - indicated that the air/fuel ratio was not right due to the misaligned plenum...

all good now!

Good deal

[sergbaja5t]

Im have similar issue as well, since I replace the evap valve under the plenum. Ugh this car is such a woman, making mountains out of molehills.