Please help AFP lack of power on somedays

[Dubcessed]

So I've noticed for the past couple of months that every now and then my car seems to have very poor performance. Somedays it feels like it has very good power through out the rpm scale and other days it feels like my old 2.0l and can't get out of its own way. The only mods are a drop in K&N air filter and AWE Tuning cat back. I just can't seem to figure out what it is that's causing this random power loss. I've tried searching the forums, but I didnt find anything matching my issues. It's not stalling or running rough. I have no check engine light. But I have noticed that it doesn't have the same exhaust tone as a VR6 anymore. I replaced the post cat O2 a few months back and put new NGK plus in it at the same time. Nothing seemed to make a difference. Any help would be more than greatly appreciated.

[masterqaz]

Stop driving on somedays and you'll be good

Is the issue seemingly weather dependent? Wires can be an issue. I'd start with the basic cheap stuff if your not diagnosing anything. Plugs(which youve done),fuel filter, wires.

Intermittent problems are the worst to figure out and you've got to be ready to test things at all times. Especially when the computer doesn't pick up the issue.

I'd suspect a lean condition that's not bad enough to trip anything. This could be caused by a dirty Maf sensor which I've found are pretty common when people start changing to aftermarket filters.

[Dubcessed]

The weather doesn't seem to matter. I forgot to mention that I changed the fuel filter a few weeks ago and that didn't seem to help either. I've tried doing what diagnostics I can, but I don't have access to a scanner which would help a ton. I didn't even think of seeing if the MAF was dirty, would make sense if there was a little too much oil and the K&N. I picked up a can of MAF cleaner on my way home today, gonna give that a shot and see how it works. Thanks! Oh and I forgot to say that I've also noticed a little bit of hesitation on light accelerations too...doesn't always do it tho and it's barely noticeable when it happens but just enough to feel it.