Home › Q&A › Tuning

Can a stock Gen III PCM's fuel calibration be changed without purchasing HP Tuners or similar commercial software?

Yes — there are free options for Gen III computers. HP Academy covers two:

  • LSDroid + TunerPro: free, open-source reflash tools for the P01 (1999–2002) and P59 (2003–2007). You buy a compatible cable separately (HP Academy names OBDLink and OBDX Pro VT). Less user-friendly, with community support only.
  • PCM Hammer + TunerPro: free, actively developed, works with more interfaces (such as the AVT-852), focused on older LS computers, with no customer support and a steeper learning curve. HP Academy hadn't tested it directly.

Save a copy of your stock file before writing anything. See computers & tuning tools.

Want to do it yourself? See who tunes it, and how to learn.

Confidence: medium — sources disagree or are limited; check the sources below.

Community discussion

Related questions

Sources
  1. 4 Popular LS Tuning Software Options — High Performance Academy