pulled my plugs and the tips on all of them were white. I think the engine is running lean. I was told that you can clean the maf sensor if it is dirty. Is that true? What other possible reasons can it being running lean? I changed the o2 sensor already.

 

Having white spark plugs is actually ideal, were ALL of them white?. What else makes you think the engine is running lean? Does it have a miss?

You could check to see that the TPS (throttle positioning sensor) is adjusted properly, so that the closed throttle position switched is triggered at the correct rpm.

 

Using a K&N panel filter on a VG can cause it to run lean.