TOPIC: 2018 GMC Sierra 1500 6.2L V8 - Starting from scratch

I don't think this picture came through the first time.....

I should be able to push the white clip back and slide the two pieces apart, correct?

Possibly, or there could be another locking tab on the other side of the connector that this pic doesn't show. That grey one looks like it might be the assembly the pins get inserted into, before the external shell goes on the connector.
I appreciate your caution in not wanting to break the connector, but they're built to withstand quite a lot. That said, they do degrade...but this is a fairly new/recent vehicle, so you probably don't have much to worry about.

I love the word dork!

Well, ran in to a bit of a snag. Finally got the two pieces apart to verify the identity of the correct extender/harness....and it is different from the one Ballenger customer service advised. I emailed Chris at Ballenger a picture of the one installed to see if they can accommodate me. I might have to just go old school and tap in to the wire itself! Stay tuned!

If it was their mistake, I certainly hope they make it right for you.

Yeah, they're good people! They are working with me.

They don't have a harness that will fit my application. The harness they have that is similar to mine has a trapezoidal notch in front of the #3 wire where as mine has the notch in front of the #2 wire. Otherwise, they look identical. Conferring with Chris at Ballenger, I'm simply going to "delete" the trapezoid notches and go from there.... They should fit together minus the notches.

So, another delay in getting things installed. Work in progress....it'll be worth it!!!!

Stay tuned!

I'm watching your progress eagerly, sir, and hope that your celebrations today involve working on your truck!
Happy 4th!

Thanks! Happy 4th to all!!

Stay living FREE guys!

While I'm waiting for the harness to arrive for the EFIE's, I'll update on the MPG's...

It looks like the ECM is up to its usual shenanigans! The mileage has slowly fallen. The last fill up showed 12.5 down from 14.9 with the intake and exhaust mods. Once I installed the ignition upgrades, the average spiked to 17.8 - but that was only for a short time. I'm not sure if I mentioned, but the initial install of the ignition upgrades saw a ton of water and steam coming out of the exhaust pipe leaving a puddle of water the size of about a small dinner plate. It was purring like a kitten. That is when I got the spike in the mileage. It didn't last long, though. The truck runs great and it gets up and goes! But, no more steam or puddles of water at the tail pipe. In fact, it looks like it's running rich, now. Here's a pic of the wasted money out of the tail pipe!!

You may be running rich, but you may also be blowing the carbon (that came with the new to you truck) out of the pipes. I'd guess a bit of both.

Andrew, you've done wonders in getting the truck to burn fuel well with your cold air intake/high flow filter and higher voltage ignition coils/zero resistance wires/wider spark gaps (I think you've upgapped with torquemaster plugs, right?) - more/denser air and bigger spark will cause an unmodified computer to deliver more fuel to stay at 14.7:1.

Check a scan tool for how many grams of air per second at hot idle the MAF says the engine is sucking in - it should match the metric displacement of the engine (5.4L should suck 5.4g/s, 3.5L should consume 3.5g/s); if it's higher, as I suspect yours might be, that's part of why your mileage has dropped. That air goes through the 8 cylinder air pump under your hood and hits the o2 sensors, which makes the computer go "waitasecond, that's more oxygen than is supposed to be there! I need to pump more fuel!!"

as I've said previously, we have to take control of our computers with add-ons like the EFIE and MAP mod. the EFIE allows you to trick the computer into NOT sending as much fuel to lean out the air-fuel ratio (maybe up to 18 or 20:1) based on the o2 sensors, by telling it there's less oxygen present than there actually is. The MAP mod allows you to alter the timing for optimum power from that "lean" charge. (among other things that help control injector pulse duration)

My experience is such that the groove with ignition improvements causes an improvement in efficiency, but I've fine tuned and improved the system for consistency with EFIE and MAP mods. You're halfway through the process with this truck, give or take. now get that groove on. Don't make one of us come down there! ;-p

Hey Andrew, a question for you. I have you reset your ecu after you installed these goodies? I might have missed it if you said you did.