My check engine light keeps going off and on. The code keeps coming up lean burn and I have chased it around in one exspensive circle . It all startedwith the ox sensor I have also replaced two coil packs, spark plug wires & plugs, mass air flow sensor and pcv valve. The pcv seemed to help it a lot but the check eng light still keeps coming on.
can anyone help me? :? :( :? :(

Oxygen sensor was a good place to start, and the MAF also, although the MAF can be an expensive 'shoot from the hip' repair.

A bad plug or wire cannot cause a LEAN condition. It'll cause rich, but again, not bad to change them anyway.

Taking this to the next level, now that you have the basics out of the way:

1. Look for an exhaust leak. Either from the mating surfaces of the manifolds to the heads, or from cracks. Could even be a leak EGR tube/valve, or even possibly the union at the crossover pipe under the Throttle body. Anything in the exhaust BEFORE the O2 sensor.

2. Consider pulling your fuel injectors and inspecting them. An injector running lean will have more carbon/oil buildup on it than a properly firing injector.

EXCELLENT post by the way. Very descriptive, and got us all on task right off the bat.
Only problem is your username. There are internet 'bots' that do nothing but scan the internet for email addresses all day long to add to 'spam' lists.

Send me a private message if you'd like to change your username.

When changing a maf you should disconnect the battery for 20 minutes and then reconnect. Did you happen to do this?