Ok guy's I am a little confused on these scanners and programmers. What do I need if i want to make changes to the pcm. Such as temp the fans turn on and things of that nature. I guess the scanners just tell you what's going on and then you need a programmer to make the changes you want. I really want to learn how to do this but not sure what exactly it is i need. I here about the hand help programmers but my understanding is they limit what you can change to only a few things. The computer based ones like tuner cat all you to change just about anything? Like I said I am really confused. I just want to know what i need to use to see what's going on and then what I can use to make changes. Thanks in advance for any guidance you can give. I am an IT manager so I know computers but not in relation to cars.

 

A scanner is totally passive. It can read the various sensors and some calculated parameters (e.g. - pulse width, learned fuel corrections, trouble codes) and display them, or log them over a period of time. It can not change anything in the PCM, other than (on some scanners) the ability to clear a trouble code.

A programmer can access the "program" parameters, and change them. Simple things like tire diameter, fan on/off temps, and more advanced things like knock retard attack and recovery rates, PE mode target A/F ratios, spark timing maps, etc.

The "hand held programmers" are EXTREMELY limited in what they can do. The only one I am aware of is the Hypertech, and its "performance program" is next to useless. Then there are a couple "modules" like the JET that plug into the PCM, but they can do even less. Not useful for any sort of serious programming.

There are only a couple choices in programmer software for your OBD-I LT1 - LT1_Edit or TunerCat.

To do a good tune, you need both scan software to tell you how the engine is performing, and tuning software to allow you to change that performance.

 

Thanks Injun for that. i just ordered the cable and was looking to find out what else I need. I'm sure i will have a lot more questions. Which do you prefer. tunercat or lt1 edit? What scanning software should I get?

 

Tunercat is cheaper and has no VIN locks. It will do virtually anything you want.

TTS Datamaster is a good scanning/logging program. http://www.ttspowersystems.com/DataMaster.html

 

Thanks again. i will look into those.