i recently swapped throttle bodys and after about 40 miles the exsaust note changed on hills sounded like was running out of fuel but was still pulling fine. So i hooked my scanner up my and found it was reading 2psi vac at idle and the most it would read was 12 on decel down hill so i swapped map for a nother i had and now reads 8 psi at idleand 14. i have a vacum gauge mounted to a piller and it reads 15 at idle and around 20 on a decell.So i was wondering does it all ways read lower? It did fix the sound it was making by changing it out.. Thanks for any help

 

well i tryed my scanner on my son in laws99 ram and that convinced me to buy a new map censor ...his reads 0 vacum at idle and 20 when you hold rpm around 2000..so i figure that my scanner has a gremlin laughing its head off or there all bad units in our riggs lol