DIY PCM tuning
 

So the honda guys have hondata What can I get for my blazer? obivously I can get someone to tune it for me but I want the ability to do it myself and I can't seem to get google to help me find someone who sells the gear to change my own settings in the pcm anyone know?

well if you've got a spare $500 there's HPTuners - I think beyond that you're looking at the usual handheld programmers like at SUMMIT

HPTuners 'free demo' is useless to looking at your specific vehicle without their cable but it does come with sample files that give an idea of what kinds of stuff you can mess with

Once GM went from ODB 1 to OBD 2 the days of wiring up a connector and programming with a laptop with free software kinda died.

If you stumble upon an underground of free OBD 2 programming I'd love to hear of it - I've looked around a fair bit, but I may not be asking google the right questions either... (or know the right people)

with honda ecus they use a removable Eprom chip that has been put into a modified ecu. this chip is basically what runs everything in your vehicle. that is on an obd1 ecu. also for obd2 hondas they make adapters and run obd1 ecus on thier obd2 car usually by modifying a P28 ecu by putting a programmable eprom chip into it.

for obd2 vehicles. there are programs you can buy for them just like professional dyno tuners do. names i dont have. where you can plug into your car/truck and adjust your fuel map and stuff like that. vw/audis kinda have something like that called a vagcom. a wire that connects your ecu and laptop.

i guess none of that really answered your question...
try googling obd2 tuners or obd2 to usb cord. and they should have a software to go along with it.

out of experience i would avoid any ebay cords

I'm liking the look of the HP Tuners set up, and with the price of fuel and how much this poor thing burns if I can tune it to save $1 a day I'd be happy!
guess I'm going to be doing more research on them seeing as how there doesn't appear to be a lot of custom systems out there

We use Hptuners for everything. Throw a wideband in for ease of tuning and go to town. As long as you know what your doing its worth every penny.