2003 gmc yukon slt , where to start?

[ehall8702]

so motor is stock, has CIA, will 05 electric fans and add on harness, 1 7/8 primary to 3" long tube headers, 3" y pipe , 3" all the way out with a single chamber muffler. stock size tires, headers will be wrapped also. i will be doing these add ons this weekend. i want to delete rear o2 since cats will be gone, i want vatts gone, evap stuff gone (have the block offs on the way). i think i am capable of doing that stuff on my own. i have never tuned before but been digging around on the sto k tune and have found where alot of things are.

things i dont know is what pins i need for my fan harness. secondly id like to firm up my shifts, maybe get rid of the ec3 controlled slip stufff possibly. thats unless someone has a reason its a bad idea.

i think this is a flex bc there r e85 stickers in gass fill lid, that means bigger injectors which will be nice when i grab a cam. i want to start trying to optimize my engine the best i can with what i have, more so to familiarize myself with the tuning process. i have never attempted a tune before. i have a wideband i think best spot is where y pipe dumps into a single pipe? the yukon gets about 15mpg right now, as long as it doesnt drop drastically i am ok with that, up is better unless it means the truck gets more sackless than it already is! stock tire size on 3.73s with a 5.3 shouldnt be so blah down low, my 5.7 in my 97 got way more get up with 230k on it.

is there any other stuffi should be looking to change t help my truck out? im not opposed to buying a book or paying for kn owlede but i dont learn well from just reading things. i want to learn while this engine is basically stock to lessen the chance of messing the engine up, tho i do have another 5.3 and a 6.oh sitting on stands! once i get a good grasp on tuning this truck will get a stage 2 or so truck cam and im about to do a 6.0 swap in my 97 , ill be figuring out the segment swap stuff there, but i think i got thst under controll but i would like to have a good idea of what im doing not just copying what i see on a video or page before i start engine modding the 6.0.

thanks in advance for the help!

[kevin87turbot]

There are several things that will help the power, torque and throttle response on that model.

Eliminate all delays in PE mode.
You can add a couple degrees timing.
Reduce torque management.
Disable Abuse Mode.
Increase the ETC limits in the TM tab.

[willeh_ca]

I'm not a tuner either I'm still learning so take this with a grain of salt. Wide band included instructions likely give the best direction for installation location. The chopperdoc videos on YouTube were the most how-to friendly, Goat rope garage is good as well, but I really liked chopperdoc. For the transmission search for the BlueCat program link on this forum it's fantastic and very useful for shift points. For wiring harness stuff go to Lt1swap.com and look up the specific info for your vehicle, that'll give you the pins for the fans.

[ehall8702]

Thanks man, appreciate the input. Think I found the pins I need but will check there to verify. I read the instructions with the wideband, says to take out a o2 but in my head I only see that reading one bank only, I'll email the company and see what they think and recommend .

[blindsquirrel]

You can't adjust fueling in the tune bank-to-bank anyway, so there will always be some mismatch between them even if you had dual sensors. A single sensor after the merge just gives you an average and the error is split between banks again - one side still rich, other side still lean. On an engine with no vacuum leaks or flaky narrowbands or junk injectors the difference between banks should only be 3-4% at most. Save your brainpower for stuff that matters.

[ehall8702]

Yep I do tend to over think,I'll just take an o2 out and use wideband there and replace when I'm done, thanks!

[ehall8702]

I will be digging around to locate these parameters, I appreciate the advise, hopefully I can make the little 5.3 come alive , even the wife is a bit disappointed as the 98 Yukon with 350k on it had more get up and go off the line. She loves the newer Yukon for EVERY other part of it tho.

[blindsquirrel]

All those trucks are gutless because of power enrichment effectively disabled in the stock tune. The way they did that may improve emissions in some narrowly-defined laboratory test but kills everything else, even fuel economy, because you have to use way too much throttle all the time just to get the thing out of it's own way.

[ehall8702]

Most definitely, have to hammer on it waaay too much. Not too long ago took a trip to Missouri from upper Michigan, 12+ hrs , it was this yukons first road trip and it was hard to even pass anyone at 65-70 , have to floor it , my lady doesn't like to floor it so let's just say it was slow going when she was driving. When u was driving it's like the thing just hits 80 and that's it, no more. After removing all the bs the factory tuned in, this thing should be as good or better than the 98 I'd imagine right? After efans, exhaust and CIA I'd imagine I will see decent Improvement also?

[ehall8702]

Only CIA on so far , Sunday I'll get it up on my lift and get to the exhaust and fans. So I went thru and disabled the vvats, codes for rear o2s, all the base stuff and did sum of this


Eliminate all delays in PE mode.
You can add a couple degrees timing.
Reduce torque management.
Disable Abuse Mode.
Increase the ETC limits in the TM tab.

Think I added 3* to base timing, and turned off the abuse mode and a few things else. Changed things quite a bit , haven't adjusted shift points yet,still playing with the bluecat deal trying to understand exactly what I'm supposed to do with that info.

I haven't figured out how to log yet,but will get a log file as soon as I figure out how to. Probably will do that after the wodeband goes in this weekend.

Just the mpvi2+ was worth the money to use as a scanner ( was going to get a used modis before I got this module) , but the extra $100 to even disable the rear o2s and minor tweaks so far makes this a great investment.

[ehall8702]

https://youtu.be/nG8FnZfhCew

Exhaust done, going to change to a different tip since she doesn't like that one.

[[email protected]]

How much increase in the ETC table? Entire table?
I've been working on my truck and have trans working pretty good but try to get a little more power out of the motor and definitely the umff lower rpm.