OK. I finished my exhaust header upgrade to the Magnaflow and replaced my thermostat and it runs nicely, but now my check engine light came on. I need a code reader. I did the search and found a thread from June 2012 with a recommendation for the Actron CP9580 w/ Code Connect. I obviously want to spend as little as possible for a user friendly reader. How say you all?

 

Hi Hooty-Hoo hold off on that code reader until you put some miles on the hummer I know I purchased a Iats put it in, engine light was still on. even the code reader was telling me the same code.
figured faulty new part didn't want to mess with it that week.
The following weekend getting ready to bring back. boom light was off went about 100 miles before engine light went off been about 3 months now still good. Hopefully that's all yours will be

 

I tell everybody to go by Advanced Auto or Autozone and they will read a code for free. Pretty much any one of the auto parts places will do it.


Or, I just picked up one of these:
Autel (MaxiScan MS309) OBD-II Code Reader / Scan Tool, $24 on Amazon. I bought mine off a place called midnight box for $11. And I also bought a generic Bluetooth code reader there for $10. The Bluetooth model links up to my phone and has some pretty cool features. It can display a bunch of data in real time, the ap was called Torque, it's for Android and free. Both of them worked on my Hummer, but I didn't have any codes.

 

Those are two of my suggestions - auto parts stores read codes for free, and for buying one I'd rather have a bluetooth that can connect to an Android phone. I actually bought my 15 year old a bluetooth one as his little pick-up is throwing a code, but really I want to test it and possibly buy myself one. Supposedly with that I can pull up real time data while driving as well as pulling codes and such. I haven't played with it yet (he hasn't taken it out of the package).

 

It's really quite cool! I think they are all pretty much the same as far as being able to connect to the Torque ap. Just messing around with it there are 5 pages you can add gauges, graphs, etc to. It would be real cool to display it on a lcd radio screen..... you can see all the data off the ecu, pretty neat!

 

Have you had a chance to go buy the auto parts store?or purchase any of those cool diagnostics tools waiting to see what code #s pop up for ya. just remember put some miles on her first before purchasing parts you may not need as long as she running nicely. you want computer chip to clear itself out.