So I've done a search and found out that the pcm4less upgrade is something I wanna do... I'm contemplating 35s over 33s and it'll be nice to get a little power back to combat the bigger tires. That's nothing new...... But what I'm wondering is, does the tune need to be changed after each mod....? My H3 is stock now with 33s (285/70/17) but I plan to do an airdocs and possibly exhaust.... Probably not at the same time... Will i have to send the pcm in after the intake, after the exhaust and after the 35s??? Would I just be better to wait til I get the mods done? I want the benefits of the pcm4less even if I'm all stock right now. I just don't wanna take the pcm in and out to send it in........ I couldn't find any threads in the search that answered this. I emailed the company and asked and I'm waiting on a response.... Just wondering if any of you hummer gurus could take a sec to help a nooN out.....

 

Just heard back on my email.... Cold air intake makes a difference on the tune. Cat back exhaust, not so much.... It will need to be sent back in once 35s are installed to set the Speedo right.... Helpful info.... I'll be on the hunt for a cai so I can get the pcm upgrade and run like that while I do other stuff... I'm sure all the long time forum users know this already but thought I'd share what little info I've gathered.

 

I do not remember what year H3 yours is, but generally, the answer is: do all your anticipated mods first, then do the tune set for those mods.

If you have an 08+, even if you do not have an Efan, you may want to consider adding the Efan patch into the PCM tune so you can easily add the Efan later without sending the PCM back to add that Efan patch later. With the 06/07 the Efan is controled by a sensor in the radiator hose not the PCM.

So.... do your tires, intake, exhaust, PP TB, etc., then get your tune.

 

Doc, it's an 06..... Talked to Kelly and she clued me in a little bit on what I wanna do... I'll do an intake and the tune. I wanna get my roof rack and recovery gear next... I've got good tread on my 285/70/17 ATs so once I wear those out a little, I'll hopefully have the cash saved up for 35s.... Then I'll send it back in and get it programmed for the 35s.... That's the plan for now at least....