My hypothesis is either:
1)the person you were talking to needs to lay off the crack pipe
2)or they're just stringing random words together for kicks
3)or making up stories due to get attention...
I don't even know what an 'untuned PCM' would mean...is he saying it's stock, i.e. no aftermarket tune flashed in it? some sort of magical PCM untuning power? sorry if I sound like I'm being a ass or something about the guy but no part of what your talking about makes any sense. perhaps the guy has just been fed incorrect information and he's parroting that back to you or something, but its basically just gibberish.
first off. a PCM (every PCM) contains tables of data which it uses in various ways to calculate how to run the engine...the data that a PCM contains is arrayed in various tables, so the engine sensors feed live data to the PCM, the PCM takes this data that the sensors are providing, uses the data contained within the tables to make calculations on things like how long to pulse the injectors based on how much oxygen is being taken in, etc...
Okay, so the factory has a stock set of data that they input into these tables for the PCM to use in it's calculations. So when someone talks about getting a tune, or custom tuning or something....what is going on is the tuner is just changing the data values to something else.....so from that standpoint, EVERY PCM has a tune in it, whether it be a stock tune, or a custom tune, its all the same data tables, albeit with different values....so saying some PCM is 'untuned' is just nonsensical, any PCM without a tune wouldn't run the vehicle. it wouldn't do anything.
of he's claiming that he installed a '96 PCM into a '98 and gained 35 hp...that's likely just lying...first off the '98 PCM is a 4 connector PCM, whereas the '96 PCM is a 5 connector PCM, and with different pinouts. so he would have to re-pin the connectors, and ADD a 5th connector to the harness...they're not directly compatible....also the '96 and '98 PCMs are based off the same platform with the same basic computing power and speed, they are primative PCMs with low resolution data tables.....not to mention that the '98 PCM runs alot of additional sensors that the '96 PCM is not equipped to handle (i.e. fuel tank pressure sensor, EVAP vent valve, different EVAP purge system, etc)
so after all that, no, your '96 PCM isn't going to give you any benefit in the '98, its not even compatible with it without ALOT of work....however a 2002 411 PCM can be made to work with the '98, offers much more support, faster processor, higher resolution tables, and several other benefits...that would be the PCM swap worth doing in the '98...
