14burrito

That blue tag nor the white letters on the tube provide any sort of feedback or insight into what it is?

His name is Lew, hence the DiabLEW

They install a bypass block that has no tstat in it.

Second EBC. Seems like there are a few people out there, not GM specific, that state their Powerstop tend to fade when toying. They swapped out to EBC and had greater, percieved, performance.

IMO bags are a bandaid. A properly setup WDH is the way to go and not overloading the TV. A good view here if you have 10minutes.

Just looked it up, looks like its standard in the Z71, max trailering and optional across the board to get the dual speed tcase. Single speed RPO: NP0 Dual speed RPO: NQH

Tcase either optioned 4hi or 4hi/4low. The dual, which includes 4low, in part of the max trailer package IIRC which has 3.42s. My 3.09 unit, not max trailering, is only 4hi.

Wasnt aware, very nice!

You will get a few different responses (HPTuners or Diablo probably the top 2). HPTuners is more hands on, Diablo will be more hands off. I have the Diablo Intune I3 and will probably have Lew write me a tune. Consensus though for longevity is increase pressure and disable TCC lockup for the first few gears.

You have dual speed tcase? If so, 3.42 is correct. If not, 3.09s.

All good, figured I'd clear it up so we are all on the same page

Curious what made you choose the sureflow vs the new 70C or pill flip options?

My sample came back good, so much so Blackstone questioned the mileage on it. Makes me wonder if the previous owner did a trans service or not. I dont think the pill flip can be done on the vehicle due to location. Been a while since I was under the Tahoe, but from the picture posted above, top of it's kind of close to the body. The internals are removed via the top, not the bottom. Trying to get the circlip off would be tedious I believe. You mentioned Katech 17 above, what are you referencing? The Katech 174 is an engine thermostat, not ATF circuit related. I only brought that up in the OP because of, what I perceive, these Tahoe's run warm. I live in AZ and I had some high ECTs just driving around town, not a fan of their cooling strategy. I brought up my concerns directly with the dealer(s) and GM corporate and we were told by the Engineering Department, my concerns were not valid and the Powertrain was operating within the designed temps....and then a year later GM released their TB for a lower temp trans tstat...

Once the fluids swapped, either get the new tstat, flip the pill or get this. https://lincodieselperformance.com/shop/ols/products/ldp-l5p-trans-cooler-bypass-valve

IMO, Only thing would be to check the monolith / cone for proper honeycomb without much wear or clogging. Have you yet tried doing a hot run / cat burn off procedure? Everytime I do a seafoam procedure, I follow it with a high RPM run on the freeway for 10/15min. Drop down the gears, get the RPMs high and cruise on the freeway for a while.

I know wiring and resistance checked OK but you able to swap post cat sensors between banks? If the fault goes to 1, sensors reading incorrectly. Stays in 2, further diagnose.

Wasn't an oil spill, I got sloppy cleaning the mityvac. Cleaned the container prior to pulling the fluid so I could get a clean sample to send out.

Mityvac FTW, bought mine off ebay. Comes with hoses that work for the ATF fluid exchange.

Interesting. All that comes to mind would be velocity vs volume.

So Airaid tube and airbox mod = no dice?

This isn't a dealer issue IMO, this is a GM issue at the core. GM has attempted to have lawsuits dismissed against their products (most specifically their gearbox's) with statements along this tune: warranty applies to parts with manufacturing defects, not design defects. Quick google search will yield some reading materials.

Most certainly wont hurt. Most people do a pan exchange every 10/20k miles. I took a sample, sent it in to Blackstone. Result came back pretty decent so I do a 5 to 6 quarts pan fluid exchange every 10k.

Collapsed lifter, I believe, you'll have a hard misfire fault. I guess the first thing to do, if you feel the valve trains noisy, remove the covers and check the movement on all the lifters and then go from there.

Ah that spec lol I thought it was because I used Nm unit first lol Gutentight

FWIW, mode 6, my cylinder 7 has the highest counts.