What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Grady_Wilson]

Just got done swapping both upstream O2 sensors.
No codes, just 162k on the originals and I know older O2 sensors get 'lazy' and tend to not meter as well.
Started her up and it seemed to idle a little smoother.
We'll see if I get better drivability or more MPGs.

Driver side was the one that is harder to get to, being as the front driveshaft is pretty much in the way.
That one broke loose without too much drama using my O2 sensor socket and a wrench on the end.

Passenger side I could use my ratchet but I needed to use a big breaker bar with a cheater pipe on the end to get it to break loose.

 

[Doubeleive]

Just got done swapping both upstream O2 sensors.
No codes, just 162k on the originals and I know older O2 sensors get 'lazy' and tend to not meter as well.
Started her up and it seemed to idle a little smoother.
We'll see if I get better drivability or more MPGs.

Driver side was the one that is harder to get to, being as the front driveshaft is pretty much in the way.
That one broke loose without too much drama using my O2 sensor socket and a wrench on the end.

Passenger side I could use my ratchet but I needed to use a big breaker bar with a cheater pipe on the end to get it to break loose.

You should clear the obd system when replacing the 02 sensors so it can relearn the new ones properly, even if you did not have any codes or problems
so either disconnect the battery use a scanner

 

[Grady_Wilson]

You should clear the obd system when replacing the 02 sensors so it can relearn the new ones properly, even if you did not have any codes or problems
so either disconnect the battery use a scanner

I took a short drive and it seemed to drive much better.
Will clear everything in the morning with my scanner.
Thanks for the heads up.

 

[mikeyss]

I've listed my Tahoe for sale in the classified section. I am selling it mainly because I do not want to fix the rust on the body (the frame is in great shape), I want air suspension, and lane keep with adaptive cruise - something the Tahoe can never have.

 

[Doubeleive]

I've listed my Tahoe for sale in the classified section. I am selling it mainly because I do not want to fix the rust on the body (the frame is in great shape), I want air suspension, and lane keep with adaptive cruise - something the Tahoe can never have.

are you sure you want those features?
1. lane keep sucks because it only works when there is really good paint marking on the road, which is basically never, at least around here
2. many people dislike the adaptive cruise.
option 3 I would at least try to find one that has both regular cruise and adaptive cruise, which can be hard to find. generally the only way to tell is too see if it does both by pressing the button. that way if you decide you do not like it then you still have regular cruise. if it has adaptive cruise only then your stuck with it if do not like it.
the other features like forward detection, etc are annoying because they will activate without reason "sometimes", you can power thru it with the big pedal.
it comes with a flashing red light on the window and a surprise seat vibration. (the drivers seat has small vibrators on the left & right side, inside the cushion) and as a pro tip if it gives a service message or error, it's generally the left side vibrator wire harness that gets worn from getting in & out of the seat.

 

[Grady_Wilson]

Not my GMT900, but a friend's.

It's a 2013 Avalanche, swapped both upstream O2 sensors and they both came right out.
Zero drama like with my Yukon.

 

[SpareParts]

Ac problems continue.
After changing a bad line, after the vacuum test for 1/2 hour, charged it with 4lb of R134A.
Pressures are still good but it is not blowing cold air. Just kinda cool.
I'm wondering if i have a bad actuator not moving the door. I have no codes from the HVAC.
Where is that actuator? I assume it is called Blend Door Actuator?

 

[PG01]

View attachment 487014

From swapping the radiator, hoses, t’s and belts? C’mon now…. I had to break a wire somewhere… ffs fml

I finally put everything in Saturday morning, filled the overflow, started it and it was running like crap so i shut it off. I looked to be sure i plugged the maf back in because thats all i unplugged. It was in so i cleaned it real quick, plugged it back in and started it again and still running like that so i put some more coolant in and shut it off, grabbed my small scanner and got those codes. At this point it started raining and i didn’t feel like getting wet so i closed it up, locked it up and walked away. Ill poke around today a little.
Thank you @Fless for looking that up for me.
Ty @SpareParts for your input.

Probably the maf unplug it and see if it runs any better, it wont run good but it puts it in speed density mode and then kind of relies on the map sensor, it might cough or sputter a bit at first

Finally got a chance to dive a little deeper. Started right up but again running like crap got it into garage, popped hood and went to get scanner. Came out and it had stalled and now it cranks but don’t wanna start…unplugged the maf and plugged back in, screwed around with the few grounds i could reach but still just crank no start now… ffs

 

[swathdiver]

I've listed my Tahoe for sale in the classified section. I am selling it mainly because I do not want to fix the rust on the body (the frame is in great shape), I want air suspension, and lane keep with adaptive cruise - something the Tahoe can never have.

Mike, my Cobra dash cam has lane keep assist. Of course it doesn't slow the car down when it runs up on someone but it does warn you.

 

[swathdiver]

Just got done swapping both upstream O2 sensors.
No codes, just 162k on the originals and I know older O2 sensors get 'lazy' and tend to not meter as well.
Started her up and it seemed to idle a little smoother.
We'll see if I get better drivability or more MPGs.

Driver side was the one that is harder to get to, being as the front driveshaft is pretty much in the way.
That one broke loose without too much drama using my O2 sensor socket and a wrench on the end.

Passenger side I could use my ratchet but I needed to use a big breaker bar with a cheater pipe on the end to get it to break loose.

If memory serves, it's the downstream sensors that calculate the alcohol content. Either way, reset them with the scan tool when you are running E10 gasoline, like right after a fill up.

I changed them out in the pickup a few months ago and today is the first time we've had her on gasoline in a long while. I'll be doing the same thing after dinner.

 

[homesick]

Ac problems continue.
After changing a bad line, after the vacuum test for 1/2 hour, charged it with 4lb of R134A.
Pressures are still good but it is not blowing cold air. Just kinda cool.
I'm wondering if i have a bad actuator not moving the door. I have no codes from the HVAC.
Where is that actuator? I assume it is called Blend Door Actuator?

I had mine checked and charged this time last year. He couldn't find the leak, so put some dye in. He told me he'd see the dye, and pinpoint the leak, this year.

I went last week. He added 2 lb of refrigerant, but didn't find the dye or leak. He says it's probably under the dash; and that he'll need the truck 2 days to find and fix.

I'm wondering if I'd be better off just getting it recharged each year. I don't know how many recharges it'd take to equal the cost of pulling the dash. And getting into the dash sounds riskier regarding mistakes being made.

Any thoughts on this? Anyone?

joe

 

[PG01]

Buy

I had mine checked and charged this time last year. He couldn't find the leak, so put some dye in. He told me he'd see the dye, and pinpoint the leak, this year.

I went last week. He added 2 lb of refrigerant, but didn't find the dye or leak. He says it's probably under the dash; and that he'll need the truck 2 days to find and fix.

I'm wondering if I'd be better off just getting it recharged each year. I don't know how many recharges it'd take to equal the cost of pulling the dash. And getting into the dash sounds riskier regarding mistakes being made.

Any thoughts on this? Anyone?

joe

buy the cans at the store and do it yourself every year. Seriously some if not most gave a leakstop or dye in them as well.

 

[Doubeleive]

Finally got a chance to dive a little deeper. Started right up but again running like crap got it into garage, popped hood and went to get scanner. Came out and it had stalled and now it cranks but don’t wanna start…unplugged the maf and plugged back in, screwed around with the few grounds i could reach but still just crank no start now… ffs

Unplug the maf and leave it unplugged, see if it starts

 

[PG01]

Unplug the maf and leave it unplugged, see if it starts

It didn’t… and tomorrow is another day doubie…

 

[homesick]

Buy

buy the cans at the store and do it yourself every year. Seriously some if not most gave a leakstop or dye in them as well.

I don't do my own labor anymore.

joe

 

[Doubeleive]

It didn’t… and tomorrow is another day doubie…

check fuel pressure....

 

[PG01]

I don't do my own labor anymore.

joe

I understand.
Can you pop the hood? Can you make a turning motion with your hand/wrist? Can you snap a quick connect fitting on a hose? Like a compressor air hose or power washer hose?
It really is that easy.
But again, i understand.
The only problem i see if its leaking out that fast is you wont have a good defrost mode in the winter because the compressor turns on during defrost to remove the moisture.
That being said, how many cars have we all had that didnt cone with factory air and all we had for defrost was hot air so theres that.
Have it filled every summer and enjoy the cold air
Good luck joe.

 

[mikez71]

... I don't know how many recharges it'd take to equal the cost of pulling the dash. And getting into the dash sounds riskier regarding mistakes being made.

Any thoughts on this? Anyone?

Dash really isn't too bad, but still time consuming.
Although if your dash is starting to crack, that might be a concern....

I've heard the HVAC case needs to be drilled apart, then screwed back together when done..
Might cost you ~8hrs? (Probably take me longer just because I'm special..)
Might as well get heater core replaced while it's apart...

 

[mikez71]

Finally got a chance to dive a little deeper. Started right up but again running like crap got it into garage, popped hood and went to get scanner. Came out and it had stalled and now it cranks but don’t wanna start…unplugged the maf and plugged back in, screwed around with the few grounds i could reach but still just crank no start now… ffs

-IF- fuel pressure checks out, maybe crank position sensor?
How's your RPM signal or injector pulsewidth?

 

[homesick]

Dash really isn't too bad, but still time consuming.
Although if your dash is starting to crack, that might be a concern....

I've heard the HVAC case needs to be drilled apart, then screwed back together when done..
Might cost you ~8hrs? (Probably take me longer just because I'm special..)
Might as well get heater core replaced while it's apart...

Heater core's a very good idea. The dash top's already been replaced.

joe