Ok previously my Talon wouldnt go any faster than 20mph which is now fixed (Blowoff valve was jammed in place) Now the car will drive and idle pretty muchperfectly except for when I am driving and I hit about 4200rpm then the car stops accellerating then starts againand keeps doing this until i let off the gas.Its almost like the car is shutting off then coming back on againjust quickly enough that nothing noticably turns off
Now the car idles pretty much perfect and when I just cruise around it drives fine. I have plenty of gas at idle the fuel pressure is at 35psiand the fuel pump is working so i dont think it is a fuel problem. The car doesnt have any air leaks and the car is in timing so Im thinkingthat the problem is a sensor.
Any ideas on what sensor might do this or even what the problem might be?

 

I would still do a boost leak test. Just because you don't see it doesn't mean it's not there.
You may have a fine boost leak that doesn't rear it's ugly head until you start hitting boost.

 

When I check for boost leaks I use the thing off of vfaq and I take my MAF off and check from there
and I had no leaks