I have a 99 NBS Z71 I have heard all the wonderfull things Nelson can do for our trucks. Also I have heard about all the wondrfull things a 02 PCM can do for my truck. I was just wondering why does the 02 make such a difference when they both get tuned. and should I do the 02 swap is there alot invloed or just keep the 99 and get it tunued?

the 99 and 00 have false knock readings in them the 01 02 do not. When the pcm sees knock it retards timming. It would be best just to get an 01,02 programed.

the 99 and 00 have false knock readings in them the 01 02 do not. When the pcm sees knock it retards timming. It would be best just to get an 01,02 programed.

Is that the only thing that is wrong with them or is there other things? :confused:

All that I know of.

Didn't the 02' have a better timing table, thought I heard that somewhere. :confused:

Also where would I go about getting one? Junk YArd?

I got my 02 PCM right from PCMforLess when I got it tuned...junkyards around here don't seem to have any new stuff. Whichever tuner you decide to go with should be able to hook you up.

I think you're right Zick, the base timing tables of the 01-02 PCM's are better than the 99-00's. I remember reading here that the newer PCM's have a different operating system and more memory also.

Don't forget that the 99's have smaller injectors than all the other years (21lbs vs 24lbs), and it's a good idea to upgrade them if going with the newer PCM. Any 00 and up 4.8-6.0 fuel injector will work (well, not sure about flex-fuel but any gas injector will work)

I know it would be a good thing to upgrade them but would it hurt to run the 02 ecm with the stock 99 injectors? Would I see any lean conditions?

I know it would be a good thing to upgrade them but would it hurt to run the 02 ecm with the stock 99 injectors? Would I see any lean conditions?
Honestly, I'm not sure. I would think it would since the 02 PCM is programmed to duty cycle less for the slightly larger injectors, but then again, theoretically, the PCM should pick up on the lean condition and compensate. FWIW, I went the other direction and swapped injectors before PCM's, and didn't experience any problems that I know of (although I didn't have a scan tool to check my a/f ratio). Check the classified section here, I noticed some folks selling some injectors for about $60.

will do thanks guys!!!!!