JBA long tube headers low end torque

I recently installed JBA long tube headers on my 2005 Tacoma 4.0L along with the URD rear O2 simulator. I also made a rook mistake and punched out the rear cats with a piece of pipe. This has resulted in some noticeable loss of low end torque that I wasnt prepared for. Nice high rpm gains but definetly need the lower end more. Now what i know is the long tube tend to be for higher RPM gains so I don't need educated on that. But im thinking if i wouldn't have knocked the rear cats out it wouldn't have effected my low end torque as much because i would have retained some back pressure. Would it be beneficial for me to put the cat or resonators back on to regain some back pressure? Would a URD MAF Cal. be beneficial? Any other suggestions to regain some low end torque. Also, i'm not worried about passing emmissions, don't have to.

 

back pressure will help your low end, newer trucks usually give up low end with headers and even just catbacks. need to look at what rpm's the motor makes it's high torque, if it is around 2500 rpm more or less you are okay. if it is around 4k or more I think your trade off is not worth it. this just my experience with dealing with headers and cat backs. I gave up on headers with OBDII, too much to deal with for the return.