My car has been doing this for a while now. When I get around 5k RPMs in WOT, it stops accelerating and it takes it forever to rev higher once it does this. It will also do this when shifting into the next gear, as soon as you shift, it keeps non-accelerating. If you part-throttle, it will rev on up to redline. I had it scanned once and afterwards had thought that it may have been the tear I found in the intake elbow. Well put on another intake elbow, same problem. What could be going on? Its not missing at all.

Here's the scan results:
5425 RPM, 45 MPH
MAP = 3.72
Throttle Sensor = 4.52, Throttle Angle = 99%
Left O2 = 796, Right O2 = 798
Left Injector Cycle = 11.3, Right Injector Cycle = 11.0
MAF = 153
CCP Duty 64.3%
Idle Air = 66 steps, Learned Idle = 21 steps
EGR = 0%
Spark Advance = 39*
Knock = 0%, Knock Sensor = 20
Closed Loop

 

No one has any ideas as to what this could possibly be?

 

Fuel filter perhaps? Mine was doing the same type of thing, though it would completely cut out around 4.5k - 5k and would the backfire, turned out it was a bad coil.

 

I'm getting ready to change the oil, I'll go ahead and try the fuel filter and make sure the coil connections are clean also.

 

Figured it out...finally!! The rubber 90" elbow that I was using from the cone air filter to the MAF in my homeade CAI must have been collapsing upon itself at the high RPMs in WOT. I put the stock airbox back on, and it pulled fine up to redline. I wonder if this had helped in contributing to the tear in my 1LE elbow .

I fixed the problem by using a 3" aluminumized exhaust turndown for the bend. It now really pulls harder than it had before. This will be polished tomorrow.