99 Q45 miss at idle

[poweroptions]

Somethings got to give. My 99 Q has 47,000 pampered miles. A miss developed at idle occassionally at 37,000. It then thru codes 138 and 139 at 40,000. We replaced both o2 sensors. Was fine for a couple days MIL came on dash. Again code 138. Went back to shop another new o2 sensor and new premium plugs. Didn't help. Went back to Infiniti (Oct.07) for a ECU reprogram at 41,000. Was fine for months now at 47,000 same damn thing. Miss is back and more pronounced at idle, MIL is on dash, consultII prints code 138/139. This is starting to irritate me and is adding up to be $$$, with no sure fix. WHAT the hell???????? Do any of you NICO guys have a suggestion????

[maxnix]

While this is technically the correct forum to post a malfunction, thou shallt not double post!