What did you do to your NBS GMT800 Tahoe/Yukon Today?

[ivin74]

Sounds awesome Sam!

X2

 

[Tonyrodz]

Finally got the muffler welded. One place wanted $175 just to weld it--it was already mounted. Found a place to do it for $75.
Once I got home from work I took it for a ride, but it feels like it has a miss or something. Took a pic of fuel trims, as usual I don't know how to decipher the info.

Anyone have any insight/idea what's going on here? Running and sounds not so great. I took the pics in park while giving it some gas. Tia.

 

[MassHoe04]

Finally got the muffler welded. One place wanted $175 just to weld it--it was already mounted. Found a place to do it for $75.
Once I got home from work I took it for a ride, but it feels like it has a miss or something. Took a pic of fuel trims, as usual I don't know how to decipher the info.

Anyone have any insight/idea what's going on here? Running and sounds not so great. I took the pics in park while giving it some gas. Tia.

Your recent work was from the cat to the back or did you do anything with the headers/collector pipes?

Maybe headers loosened up or gasket/header are a little out of alignment with the exhaust ports on the block? Is that possible?

Exhaust leaks can make O2 sensors read wonky values with the extra air getting pulled through.
If sensor thinks it is running too lean, the computer will dump more fuel in the mix. Then, all of a sudden sensor picks up on "hey, that's way too much fuel there!" and computer tells injectors to lean out.
Maybe yours is stuck in that kind of bi-polar mood swing of too little and too much?

P.S.: My OCD is making me wish I could rip the protective film off the scanner display for you... LOL

 

[Tonyrodz]

Your recent work was from the cat to the back or did you do anything with the headers/collector pipes?

Maybe headers loosened up or gasket/header are a little out of alignment with the exhaust ports on the block? Is that possible?

Exhaust leaks can make O2 sensors read wonky values with the extra air getting pulled through.
If sensor thinks it is running too lean, the computer will dump more fuel in the mix. Then, all of a sudden sensor picks up on "hey, that's way too much fuel there!" and computer tells injectors to lean out.
Maybe yours is stuck in that kind of bi-polar mood swing of too little and too much?

P.S.: My OCD is making me wish I could rip the protective film off the scanner display for you... LOL

Lol, I gotta rip it off.
There's no cats, and the downstream O2's have been tuned out. I'll check out the headers to see if anything loosened up. Hopefully it's as simple as that, but this beyotch fights me every inch. Nothing is ever easy with this HOE lol.
Only thing I did was cut out the old muffler and had a new one installed. Only difference is the new one is a little longer, and it's oval--other was round--wanted it more quiet, was too loud before.

 

[MassHoe04]

Lol, I gotta rip it off.
There's no cats, and the downstream O2's have been tuned out. I'll check out the headers to see if anything loosened up. Hopefully it's as simple as that, but this beyotch fights me every inch. Nothing is ever easy with this HOE lol.
Only thing I did was cut out the old muffler and had a new one installed. Only difference is the new one is a little longer, and it's oval--other was round--wanted it more quiet, was too loud before.

Downstream sensors don't do much, other than indicate whether the cat is working or not.

Upstreams are the ones that tell the computer what is going on with fuel/air. If the sensor thinks the air/fuel ratio is not right, it can have the computer make adjustments to the mix, which can make the engine run too rich or too lean.

You may not have anything wrong at the exhaust header/gasket, but won't hurt to rule that out.

 

[Logan5]

Returned from the cross country adventure. 10,500 miles in 33 days. 22 states, 13 National Parks, 3 Zoos, 1 flat tire.

All those miles on highways, local roads, dirt roads (where I managed to puncture a tire) had led me to the conclusion that its time for a new front end.

I am thinking upper + lower control arms, tie-rod ends, jounce stops. (I recently did the sway bar links so no need for those).

I kind of feel like my front end is sagging to the passenger side. Do the torsion bars start to fatigue over time? Maybe the key isn't set right?

I was thinking new keys (which leads me to question how one goes about setting the key height).

Do I do the knuckle & bearing now too?

Do I bother with replacing the sway bar? OR the center link? (pitman & idler are new)

Suggestions on parts?

 

[Logan5]

Oh and a couple more things I noticed on those long stretches of flat smooth highway:

Even a slight difference in the front tire pressures will cause a noticeable pull to the left or right.

The Tru-cool max 40k transmission cooler works great. I just had a new tranny installed and sustained highway speeds of 75-85 the tranny runs at 140 degrees.

The tranny runs hotter if I idle. That surprised me.

IF the ambient temp was over 100 it would run around 160, and I got it over 180 a couple times climbing mountains.

Oh another quick question, so the engine temp (as per my cluster gauge) is always right around 210. On some of those steep inclines I noticed the temp getting up to 220-230 and it worried me some. but this is fairly normal right? I shouldn't worry so much unless it gets towards the 250-260 part of the gauge?

 

[MassHoe04]

Oh and a couple more things I noticed on those long stretches of flat smooth highway:

Even a slight difference in the front tire pressures will cause a noticeable pull to the left or right.

The Tru-cool max 40k transmission cooler works great. I just had a new tranny installed and sustained highway speeds of 75-85 the tranny runs at 140 degrees.

The tranny runs hotter if I idle. That surprised me.

IF the ambient temp was over 100 it would run around 160, and I got it over 180 a couple times climbing mountains.

Oh another quick question, so the engine temp (as per my cluster gauge) is always right around 210. On some of those steep inclines I noticed the temp getting up to 220-230 and it worried me some. but this is fairly normal right? I shouldn't worry so much unless it gets towards the 250-260 part of the gauge?

Quite a trip!!
Nice dash lights, by the way!

 

[HiHoeSilver]

Lol, I gotta rip it off.
There's no cats, and the downstream O2's have been tuned out. I'll check out the headers to see if anything loosened up. Hopefully it's as simple as that, but this beyotch fights me every inch. Nothing is ever easy with this HOE lol.
Only thing I did was cut out the old muffler and had a new one installed. Only difference is the new one is a little longer, and it's oval--other was round--wanted it more quiet, was too loud before.

Was the MBRP too loud or are you too old? Asking for a friend.

 

[GreenTahoeZ71]

I drove my '04 Z71 today without even a glimpse of limp mode showing up.
I think I finally have my throttle system fixed !
It should be, I replaced the full 16 wire TAC module harness and the TAC to pedal harness as well. With a new TAC and PCM too.
I got the PCM plug and play with a lifetime warranty for about $160 bucks. Just had to do the key relearn procedure.
I made my own connector ends for the new harness with Delphi connector ends. Complete with the proper metri pack terminals.
I plan on doing an indepth thread on it. I think I learned some things on this one that will help others. I know I enjoyed how much I learned from it.
I was able to finally actually take the p0220 p2135 I got and know for a fact that it was not the wires. Allowing me to replace the TPS on the body that the crappy Duralast alternator fried with a bad voltage regulator on 3 different ones I swapped out. Went and got a Remy to solve that.
I also made sure to do the throttle relearn as well with 3 min idle in park 60 seconds off then 3 min iidle again then 60 seconds off then crank.
My throttle was super responsive today, it didn't stumble when coming to a stop, the idle behaved with the AC on too.
Now I can put the past three years and thousands I wasted on this with a terrible shop behind me and get back to restoring the Tahoe.