2000 Nissan Maxima Stalling Problems

[rgdaz]

A couple of months ago I had stalling (bucking) when backing out of the garage. Seemed that a fuel flow problem so fuel pump replaced. Continued so mechanic replaced the max sensor and car was great for 2 months...now starting again when engine cold and only when backing up. Idle is a little high at start up. Once I get going it seems fine.
So, what else might it be? Any suggestions. I don't want take it back to incur hundreds of dollars in diagnostic hour fees. Thanks.

[tigersharkdude]

Possibly a bad (or a few) coilpacks

[the converted]

Check the ecu for codes. It might not be showing any, but there could be some pending codes.

[lightsout]

The REAR BANK cat could be bad...it's causing the ECU to re calibrate the air/fuel ratio, and adjust the timing. Check the CODES and possibly replace your rear bank 02 sensor and CAT...that's my best guess.