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izzy_Britton · 12-27-2016, 12:09 AM

you COULD have the PCM/ECM adjusted to accommodate the different tire sizes.

there are 2 ways that I know of to do this, the easiest would be to find someone with a newer scan tool, like the snap-on brand. SOME of these have an option for tire size adjustment/re-calibration.

the other option would require you to remove the PCM/ECM from your truck and send it to someone who can re-program it for the correct gearing and tire size. there is a guy on ebay that does re-programming for 65$ i think it was.

-Izzy

12-27-2016, 12:09 AM	#2
izzy_Britton Registered User Join Date: Apr 2013 Location: Nor-Cal Posts: 632	Re: Q- speedo off & bad MPG you COULD have the PCM/ECM adjusted to accommodate the different tire sizes. there are 2 ways that I know of to do this, the easiest would be to find someone with a newer scan tool, like the snap-on brand. SOME of these have an option for tire size adjustment/re-calibration. the other option would require you to remove the PCM/ECM from your truck and send it to someone who can re-program it for the correct gearing and tire size. there is a guy on ebay that does re-programming for 65$ i think it was. -Izzy __________________ WHO_DCTC - Wifes 05 Z-71 Build - Now defunct as she decided she wants an Escalade too Cream Puff - LS'd Square - Slow going on the back burner Tripple Threat - 3 Wrecks for the price of one build thread Project Delongdium - Step-Sons Plastic Clad 2003 Avalanche - DONE and Delivered.