Could this be a vacuum leak?

[WeaponX]

As many of you have read I have been having a bunch of issues since I changed my fuel injectors codes p0171, p0054 & p1133 & it just hit me what it could be.
I know after the filter on my cold air intake I had to make a hole for the house to connect that is well before the throttle anyway I know it wasn’t a clean cut and the gasket doesnt fill the whole hole. Could that space be the vacuum leak? I wasn’t sure since it was before the throttle body but there are two other hoses after it but still before the TB.
The fuel pressure is good I had it tested. Sorry for so many questions

 

[Blckshdw]

At worst, you'd just be pulling in unfiltered air, since our 05s do not have a MAF. The only sensor in front of the throttle body is the air temp sensor, which was discussed in one of your other threads.

 

[budwich]

the codes are basically telling you that you have a o2 issue. Since you replaced it and it hasn't cleared much / anything, you likely have a wiring / connector issue. Your truck needs that sensor to function correctly as without a MAF, there isn't much the computer can rely on to get the mixtures correct.

 

[WeaponX]

I’ve had two different sets of O3 sensors on both uptake and down the only other thing I can think of besides of their being a vacuum leak is that after the last 02 sensor and the new cat I put on there is two exhaust leaks after that where I cut out the resonator and the two opening are far from sealed so maybe my whole issue I’m get bad back pressure and the temp being down since the exhaust can escape almost immediately after the new cat and pipe I put on?
Could that be it because my exhaust hasn’t been totally fixed yet and the back pressure loss and temp being down since it has multiple place for the exhaust to leak out? Good news on the exhaust the new one was shipped out today and should be here by Monday 😃!! That would be great if that solves all these issue of not it will have a nice aftermarket exhaust system and I’m very curious how it will look with the tip swept to come out the side

 

[WeaponX]

At worst, you'd just be pulling in unfiltered air, since our 05s do not have a MAF. The only sensor in front of the throttle body is the air temp sensor, which was discussed in one of your other threads.

I unplugged the TB and the MAF sensor and it sounded like it wanted to die and finally it did and shit off but when re connected np so I know there working.
I was just curious about the sensor that monitors temp, I did the same with thata by unplugging and then plugging it back in but nothing happened at all either way.
I truely am sorry to anyone who has read my other posts I’m just trying so hard to fix this & i’ve done everything people told me to check So from reading other people’s post here and there I’m going to try and get a smoke machine and push the smoke threw and see where it comes out of and I have a really strong feeling it’s the exhaust manifold gasket since I’ve had it on and off so many times. Since it looked good with no rips all the times I ripped it off there could be something wrong that I can’t see

 

[mrrsm]

Please post your Short Term and Long Term Fuel Trim Data... With both the Engine at Idle ...and while raising the RPM. Besides the Careful and Judicious use of Starter Fluid Sprayed-Misted around the Intake Manifold Flange(s) to look for RPM Elevation from Hidden Vacuum Leaks ... Spray a little around the SAIS Solenoid PLATE/GASKET on the Upper Passenger side of the Engine Head and check the Two Nuts- Fasteners for tightness and clear that spot as a possible Vacuum Air Leak location. If the RPM increases after spraying around the Intake Manifold Flanges... Re-Tighten them ALL to 87 Inch Lbs and NO MORE.

 

[WeaponX]

Please post your Short Term and Long Term Fuel Trim Data... With both the Engine at Idle ...and while raising the RPM. Besides the Careful and Judicious use of Starter Fluid Sprayed-Misted around the Intake Manifold Flange(s) to look for RPM Elevation from Hidden Vacuum Leaks ... Spray a little around the SAIS Solenoid PLATE/GASKET on the Upper Passenger side of the Engine Head and check the Two Nuts- Fasteners for tightness and clear that spot as a possible Vacuum Air Leak location. If the RPM increases after spraying around the Intake Manifold Flanges... Re-Tighten them ALL to 87 Inch Lbs and NO MORE.

I have to get my buddy to come back and do the fuel again because I honestly don’t remember besides he said it was normal.
I won’t lie I’m truely just a bit better than a newbie lol so the SAIS is what exactly? And on the passenger side? What’s there (trust me I’ll be on YouTube as soon as I post this lol). What do u mean two nuts?
I truely am sorry that I’m dumb when it comes to certain things guys but I’m truely trying to learn everything I can and I’m enjoying doing so

 

[mrrsm]

@WeaponX … The ONLY SIN anyone can commit regarding Automotive Mechanical Repairs here at GMTN… is One of WILLFUL Ignorance. You will never be chastised because you lack the long exposure and experience that comes from the experiences of MANY GMT Nation Members who have been working on the GM Atlas 4.2L Engine Platform for years. It is impossible to have an innate, intimate knowledge of these Motors based strictly upon ‘Mechanical Intuition’.

We all come from the same point of origin… But by using the Proper Tools, Proper Diagnostic Methods and the use of GM OEM Service Manuals (courtesy @Mooseman) along with many On Topic Threads that are available here… will make all of the difference in Helping You to come up to speed on figuring things out over time. You can Download the GM Shop Service Manual for your particular SUV at THIS Link:

Need service manuals? Get them here!

********* Please note that the FireFox browser has issues with the password handling and that these downloads are not under HTTPS, flagging them as security risks. Chrome and Edge work fine once you allow the download. ********* ATSG 4L60E Manual 4L60E Rebuild Manual 2005 GMC Envoy XUV...

gmtnation.com

The ‘SAIS’ Acronym stands for “SECONDARY AIR INJECTION SYSTEM” and the 'SAIS' Pump Solenoid is mounted on the 2005 and later model Trailblazers and Envoys Upper Passenger Side of the Engine Head… but NOT on the 2002-2004 SUVs. That port is blocked off in the Early Model Trailblazers and Envoys via a small Metal Plate placed over a High Temp Graphite Impregnated Gasket placed over the ‘SAIS’ opening in the Head and held in place by Two Studs and Two Nuts. If that Plate were to come loose… un-metered Air would enter the Exhaust Stream and cause the O2 Sensor(s) to pick up and read TOO MUCH OXYGEN. The resulting affect would cause the Air-Fuel “STOICH” to get out of whack.

Its purpose is to pump Fresh Air into the Exhaust System Stream just after starting up a "Cold Engine" to temporarily provide additional Oxygen to the Catalytic Converter and speed up the time it takes the CAT to Heat Up and allow the Upstream Oxygen Sensor to enter a “Closed Loop” Condition. This allows the PCM to begin sensing the Short Term and Long Term Fuel Trim Conditions more quickly and allow the Engine to run as close to the Magical “Stoichiometric Perfection” Air to Fuel Ratio of (15) Parts Oxygen to (1) Part Fuel. This is one of quite a few EPA Regulatory Mechanical Devices Federally Mandated under the EPA “Clean Air Act”.

I'd like to encourage you to visit my “Flickr-Bucket” via this link and familiarize yourself with the Thousands of Available Images covering many aspects of the Atlas Engine. It is FREE and always available for Ready Reference. For example… Here are Two images of the 'SAIS' Solenoid from one such Album: One WITH the 'SAIS' Device Bolted to the Engine Head... and one WITHOUT and instead, using a Flat Plate Bolted to the Engine Head to close off that 'SAIS' Air Inlet Port:

Mr. RSM Mr. RSM’s albums | Flickr

www.flickr.com

 

[christo829]

Gotta just make one minor correction, MRRSM... 2004's have the SAIS. I *wish* mine had been blocked off!

It is now.

Cheers-

Chris

 

[WeaponX]

@WeaponX … The ONLY SIN anyone can commit regarding Automotive Mechanical Repairs here at GMTN… is One of WILLFUL Ignorance. You will never be chastised because you lack the long exposure and experience that comes from the experiences of MANY GMT Nation Members who have been working on the GM Atlas 4.2L Engine Platform for years. It is impossible to have an innate, intimate knowledge of these Motors based strictly upon ‘Mechanical Intuition’.

We all come from the same point of origin… But by using the Proper Tools, Proper Diagnostic Methods and the use of GM OEM Service Manuals (courtesy @Mooseman) along with many On Topic Threads that are available here… will make all of the difference in Helping You to come up to speed on figuring things out over time. You can Download the GM Shop Service Manual for your particular SUV at THIS Link:

Need service manuals? Get them here!

********* Please note that the FireFox browser has issues with the password handling and that these downloads are not under HTTPS, flagging them as security risks. Chrome and Edge work fine once you allow the download. ********* ATSG 4L60E Manual 4L60E Rebuild Manual 2005 GMC Envoy XUV...

gmtnation.com

The ‘SAIS’ Acronym stands for “SECONDARY AIR INJECTION SYSTEM” and the 'SAIS' Pump Solenoid is mounted on the 2005 and later model Trailblazers and Envoys Upper Passenger Side of the Engine Head… but NOT on the 2002-2004 SUVs. That port is blocked off in the Early Model Trailblazers and Envoys via a small Metal Plate placed over a High Temp Graphite Impregnated Gasket placed over the ‘SAIS’ opening in the Head and held in place by Two Studs and Two Nuts. If that Plate were to come loose… un-metered Air would enter the Exhaust Stream and cause the O2 Sensor(s) to pick up and read TOO MUCH OXYGEN. The resulting affect would cause the Air-Fuel “STOICH” to get out of whack.

Its purpose is to pump Fresh Air into the Exhaust System Stream just after starting up a "Cold Engine" to temporarily provide additional Oxygen to the Catalytic Converter and speed up the time it takes the CAT to Heat Up and allow the Upstream Oxygen Sensor to enter a “Closed Loop” Condition. This allows the PCM to begin sensing the Short Term and Long Term Fuel Trim Conditions more quickly and allow the Engine to run as close to the Magical “Stoichiometric Perfection” Air to Fuel Ratio of (15) Parts Oxygen to (1) Part Fuel. This is one of quite a few EPA Regulatory Mechanical Devices Federally Mandated under the EPA “Clean Air Act”.

I'd like to encourage you to visit my “Flickr-Bucket” via this link and familiarize yourself with the Thousands of Available Images covering many aspects of the Atlas Engine. It is FREE and always available for Ready Reference. For example… Here are Two images of the 'SAIS' Solenoid from one such Album: One WITH the 'SAIS' Device Bolted to the Engine Head... and one WITHOUT and instead, using a Flat Plate Bolted to the Engine Head to close off that 'SAIS' Air Inlet Port:

Mr. RSM Mr. RSM’s albums | Flickr

www.flickr.com

View attachment 91887View attachment 91888

Thank you very much not just for the input but the understanding. When it stops raining and snowing I’m going out to inspect also I read a reply somewhere where someone said to spy starter fluid around the intake manifold and hoses as well as the outside of the TB and if the engine races I have found the leak.
I’m going to re read all the responses and make sure he said starter fluid not something like TB cleaner because yes I want to find it but I don’t want to ruin something in the process.
This is why I love you guys because you can see I’m busting my ass trying to make my blazer great again but don’t miss when I come across something that makes me look stupid 😃! Thanks everyone

 

[Mooseman]

You can use carb cleaner, TB cleaner, brake cleaner, starting fluid or even propane. As long as it's something flammable, it will work. Eric The Car Guy on YT has a very good video on using carb cleaner. It might race or stumble depending on what the PCM is doing to compensate for the lean condition. If it's already dumping a bunch of extra fuel, it might stumble with that burst of extra fuel. Basically, you're looking for a change to what it's doing while idling.

 

[WeaponX]

You can use carb cleaner, TB cleaner, brake cleaner, starting fluid or even propane. As long as it's something flammable, it will work. Eric The Car Guy on YT has a very good video on using carb cleaner. It might race or stumble depending on what the PCM is doing to compensate for the lean condition. If it's already dumping a bunch of extra fuel, it might stumble with that burst of extra fuel. Basically, you're looking for a change to what it's doing while idling.

Thank you I got a can of starting fluid today but the weather was crappy and the Eagles were on (what a waste of 4 hours that was 🤦‍♂️) so tomorrow is the day I’m going around by all house, manifold, TB anything that has to do with the air or vacuum and I’m hoping I hit it to solve this already.