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

[Bombsquad85]

if it's getting that code it's a short circuit or interference add any new electronics??

Detects a Continuous Short to Low or a Open in either the signal Circuit or the MAF sensor

what is the Value you are getting in grams/second?? <=1.26Hz

the new one could be bad if you could see if you can get a loaner or test it in someone else car

No new electronics. I need to get a scan tool to log any of the info. I only get the code from Advance when I go. Ill see if I can swap with my buddy who has a 2500 silverado with the 6.0

Thanks.

 

[Bombsquad85]

if it's getting that code it's a short circuit or interference add any new electronics??

Detects a Continuous Short to Low or a Open in either the signal Circuit or the MAF sensor

what is the Value you are getting in grams/second?? <=1.26Hz

the new one could be bad if you could see if you can get a loaner or test it in someone else car

Made a quick video of the conditions of the wires and a check for vacuum leaks. I can't tell if there is any. I hear a slight hiss from the throttle body area but I don't think its a leak

 

[Rocket Man]

Made a quick video of the conditions of the wires and a check for vacuum leaks. I can't tell if there is any. I hear a slight hiss from the throttle body area but I don't think its a leak

I don’t think the wires at the MAF are your problem. It might be that air cleaner. It might be dirty or might have got oil on the MAF from it. I would try cleaning it and the MAF.

 

[Bombsquad85]

Also heres a short clip of the exhaust. I had both cats removed. Other than that I haven't touched the exhaust.

 

[Bombsquad85]

I don’t think the wires at the MAF are your problem. It might be that air cleaner. It might be dirty or might have got oil on the MAF from it. I would try cleaning it and the MAF.

So I think you may be partially right. I'm going to replace the filter. As far as cleaning the MAF I don't think its necessary. It's only a couple weeks old with probably 150 miles on it. The filter I think its a dry filter. I've had this same one for over 2 years now lol and never oiled or cleaned it....

 

[Dantheman1540]

I think I have I the escalade variant of this unicorn glass...

View attachment 246554[/QUOTE

Wow that looks really good!

 

[Keviebear86]

I want to start by saying this may be a stupid question, please go easy I bruise lol

I'm looking to do a cam swap, already have the cam and tuner lined up. I am looking into exhaust options. I want to do long tube headers with a full 3" exhaust (not too loud, but aggressive/this is a daily for the time being). If I run long tubes, am I going to end up being catless? I can get the O2 defouler plugs if needed, but I want to keep my O2 cycles for daily/some highway runs). Any help on this matter would be great, thanks!

 

[Rocket Man]

I want to start by saying this may be a stupid question, please go easy I bruise lol

I'm looking to do a cam swap, already have the cam and tuner lined up. I am looking into exhaust options. I want to do long tube headers with a full 3" exhaust (not too loud, but aggressive/this is a daily for the time being). If I run long tubes, am I going to end up being catless? I can get the O2 defouler plugs if needed, but I want to keep my O2 cycles for daily/some highway runs). Any help on this matter would be great, thanks!

You can get y pipes with cats or without cats from most of the bigger name header manufacturers. The pre cat (upstream) O2 sensors are what your ecm uses for tuning purposes and those stay regardless if you have cats or not. The post cat (downstream) sensors are what the ecm uses to monitor cat performance and you can eliminate them physically and then have them tuned out or use spoofs like antifoulers. If you end up with cats it’s best to have the downstream sensors. On a side note some emissions places have visual inspections that look for cats and will fail you if they’re not there but some people install things that look like cats. My state doesn’t do a visual, they just hook up to the obd port and since my O2 sensors are tuned out everything passes.

 

[iamdub]

I want to start by saying this may be a stupid question, please go easy I bruise lol

I'm looking to do a cam swap, already have the cam and tuner lined up. I am looking into exhaust options. I want to do long tube headers with a full 3" exhaust (not too loud, but aggressive/this is a daily for the time being). If I run long tubes, am I going to end up being catless? I can get the O2 defouler plugs if needed, but I want to keep my O2 cycles for daily/some highway runs). Any help on this matter would be great, thanks!

If you don't need cats to pass visual inspection, just get a catless Y-pipe and have your tuner turn off the rear O2s when they tune for the cam.

 

[BG1988]

Made a quick video of the conditions of the wires and a check for vacuum leaks. I can't tell if there is any. I hear a slight hiss from the throttle body area but I don't think its a leak

you have a air leak on the intake manifold(seals can go bad)..
( you can hear it more in the center, then when the camera is on the pass side area )

or connection to the intake I would inspect every hose .. use something flammable like Axe just only use tiny squirts that stuff has Propane ..you can find the vacuum leak with that just do it on a cold engine

have a ABC rated fire extinguisher on hand just in case..


o

 

[Tonyrodz]

If you don't need cats to pass visual inspection, just get a catless Y-pipe and have your tuner turn off the rear O2s when they tune for the cam.

That's what I did, but my state does a visual. #OUTLAW

 

[Rocket Man]

That's what I did, but my state does a visual. #OUTLAW

Effin Jersey....

 

[Tonyrodz]

Effin Jersey....

Agreed!

 

[Keviebear86]

You can get y pipes with cats or without cats from most of the bigger name header manufacturers. The pre cat (upstream) O2 sensors are what your ecm uses for tuning purposes and those stay regardless if you have cats or not. The post cat (downstream) sensors are what the ecm uses to monitor cat performance and you can eliminate them physically and then have them tuned out or use spoofs like antifoulers. If you end up with cats it’s best to have the downstream sensors. On a side note some emissions places have visual inspections that look for cats and will fail you if they’re not there but some people install things that look like cats. My state doesn’t do a visual, they just hook up to the obd port and since my O2 sensors are tuned out everything passes.

There are not inspection required in Illinois (at least in my county) so I think I'd be ok without them, but I worry that removing the cats will give me a raspier tone and make it considerably louder.

If you don't need cats to pass visual inspection, just get a catless Y-pipe and have your tuner turn off the rear O2s when they tune for the cam.

I had intended on removing rear O2 sensors since they won't be needed after the tune is done. I guess I'm just second guessing myself at this point and making sure I'm doing the correct thing for my project.

 

[Tonyrodz]

There are not inspection required in Illinois (at least in my county) so I think I'd be ok without them, but I worry that removing the cats will give me a raspier tone and make it considerably louder.



I had intended on removing rear O2 sensors since they won't be needed after the tune is done. I guess I'm just second guessing myself at this point and making sure I'm doing the correct thing for my project.

@Bombsquad85 just posted a video of his Denali running without cats. His is a 6.0, but you should listen to it, just to get an idea.

 

[Rocket Man]

@Bombsquad85 just posted a video of his Denali running without cats. His is a 6.0, but you should listen to it, just to get an idea.

Oh yeah I forgot about that. He has a stock exhaust though but you get the idea. You can always quiet things down with a muffler when running headers if it's too loud.

 

[Tonyrodz]

Oh yeah I forgot about that. He has a stock exhaust though but you get the idea. You can always quiet things down with a muffler when running headers if it's too loud.

Yeah, just like mine

 

[Bombsquad85]

you have a air leak on the intake manifold(seals can go bad)..
( you can hear it more in the center, then when the camera is on the pass side area )

or connection to the intake I would inspect every hose .. use something flammable like Axe just only use tiny squirts that stuff has Propane ..you can find the vacuum leak with that just do it on a cold engine

have a ABC rated fire extinguisher on hand just in case..


o

Thanks. It makes sense. I just did the knock sensors so maybe something isn't sitting right. I'll loosen the intake manifold bolts and check to make sure it's seated properly. There shouldn't be any leaks. The manifold gaskets are newish (about a year) and the bolts are torqued properly but I'll give it a once over tomorrow. I appreciate it

 

[Bombsquad85]

Oh yeah I forgot about that. He has a stock exhaust though but you get the idea. You can always quiet things down with a muffler when running headers if it's too loud.

Yup stock exhaust with just the cats removed sounds pretty great. Not raspy at all

 

[Bombsquad85]

you have a air leak on the intake manifold(seals can go bad)..
( you can hear it more in the center, then when the camera is on the pass side area )

or connection to the intake I would inspect every hose .. use something flammable like Axe just only use tiny squirts that stuff has Propane ..you can find the vacuum leak with that just do it on a cold engine

have a ABC rated fire extinguisher on hand just in case..


o

You think I could use a spray bottle with soapy water and spray that to see if I see air bubbles like a leak from a tire?