MPFD

iTrader: (5)

Did you change the MAP sensor? the NNBS take a different part number and the pins for signal and reference swap pins in the new connector. I found this on my truck when I switched it over. It was showing high Kpa cause the reference pin was seeing input voltage. It also operates in a slightly different range. You might double check this. I ended up moding my intake to accept the old map sensor.

GREENSIERRA

that's odd cause I noticed a noticeable difference when I swapped to the TBSS intake.
I was running stock 799 heads at the time

slick_sierra

That TB is huge did you try the stock 78mm?

Jeebalow

iTrader: (3)

Do you have any more info on this? I am adding an NNBS intake and have an NBS harness so I'll have to repin. I'll do some searching and report back if I find anything.

MPFD

iTrader: (5)

It will take a new connector if you are going to run the new style Map. I would just shave off the plastic retention clips on the NNBS intake and use your old sensor. The new sensor runs in a different range and is specified for the New PCM then I have in my 99. The pins are specified on the map sensor as to their function. So if you have any question look at the two map sensors and you will see which pins to swap.

Jeebalow

iTrader: (3)

Awesome, thanks for the info man! Seems maybe this could be OP's issue?

MPFD

iTrader: (5)

Don't know, just trying to help...

Pro52R

iTrader: (16)

Is this a 5.3 or 6.0?