Noise: There's a chainsaw trapped in there?

[Tache]

I'm at a complete loss. Whenever I go over 40 mph and then apply the brake, it makes a chainsaw noise. What could possibly be causing this?

Oh and I haven't figured out how to get the bank 1, bank 2 too lean codes to go away. New MAF, two new O2 sensors, new fuel filter, cleaned injectors, new plugs and plug wires (that was fun), new air filter, and who knows what else. I've given up. I can't handle the chainsaw noise though. Any ideas?

 

[marragtop]

Do you feel anything (pulsation) in the pedal when you hit the brakes? Regarding codes, have you reset them after the repairs?

 

[Tache]

No, there's nothing in the pedal, it doesn't pull to either side, there's no give, nothing. That's the really strange part. It's not in the actual brakes/rotors. The noise is coming from underneath near the (I don't want to say it) tranny. It stops as soon as I let off the brake and give it a little gas. It doesn't do it at all unless I get over 40 mph and then try to stop. If I can coast until it gets below 30, no noise. If I have to hit my brake over 40 mph, instant racket.

And yes, I cleared the codes after every attempt at fixing it. I've read a little further on this board and it looks as if a manifold gasket may be in my future, which is no big deal since I'm already looking at a valve cover gasket. I'll just put one on while I'm doing that.