Oxygen Sensors and Gen 2 upgrade?

[AzTruckGuy]

I have researched it on both this forum and Trailvoy and this what seemed to indicate would be the Gen 2 sensor for my 2003 Trailblazer

https://www.amazon.com/gp/product/B000NW4PJC/?tag=gmtnation-20

Good thing I looked at my current upstream (manifold) sensor, because the above part would have not fit and does not have the correct fittings



So which is the Gen 2?

Here's the Ac Delco OEM center (downstream)
https://www.amazon.com/ACDelco-213-1574-Original-Equipment-Heated/dp/B000C9GNLE/ref=sr_1_1?s=automotive&ie=UTF8&qid=1471030202&vehicle=2003-47-489-96--9-6-8-7416--1-1-145-177-1-0&sr=1-1&ymm=2003:chevrolet:trailblazer&refinements=p_n_feature_keywords_browse-bin:3941084011

Heres the Ac Delco manifold (Upstream) with the correct fittings
https://www.amazon.com/ACDelco-213-1551-Original-Equipment-Heated/dp/B000C9HWQE/ref=sr_1_2?s=automotive&ie=UTF8&qid=1471030289&vehicle=2003-47-489-96--9-6-8-7416--1-1-145-177-1-0&sr=1-2&ymm=2003:chevrolet:trailblazer&refinements=p_n_feature_keywords_browse-bin:3941084011

Here is the Ac Delco professional model (downstream) which has thicker shielding than the OEM and same price https://www.amazon.com/ACDelco-213-2881-Professional-Heated-Oxygen/dp/B0010GIUTQ/ref=sr_1_3?s=automotive&ie=UTF8&qid=1471030289&vehicle=2003-47-489-96--9-6-8-7416--1-1-145-177-1-0&sr=1-3&ymm=2003:chevrolet:trailblazer&refinements=p_n_feature_keywords_browse-bin:3941084011


Here is the Ac Delco professional model (upstream) which again has thicker shielding than OEM but is way more expensive than OEM
https://www.amazon.com/ACDelco-213-2915-Professional-Heated-Oxygen/dp/B000EQP94C/ref=sr_1_4?s=automotive&ie=UTF8&qid=1471030289&vehicle=2003-47-489-96--9-6-8-7416--1-1-145-177-1-0&sr=1-4&ymm=2003:chevrolet:trailblazer&refinements=p_n_feature_keywords_browse-bin:3941084011

So I assume the Ac Delco Pro is the Gen 2? Also Denso makes the Oxygen sensors for Chevy and rebadged as Ac Delco...So why not use Denso?

Denso (downstream) cheaper https://www.amazon.com/dp/B00199BX3O/?tag=gmtnation-20

Denso (Upstream) only problem I see its says Universal cant see the fittings? https://www.amazon.com/dp/B000C5WCUE/?tag=gmtnation-20

Denso (Upstream) Air and Fuel Ratio Sensor https://www.amazon.com/dp/B000C5SG4A/?tag=gmtnation-20

 

[Mooseman]

Best thing is to look up the part numbers on RockAuto and search them on Amazon. They have better pictures of the parts, including the connector and have found them to be a bit more accurate.

 

[Sparky]

I used Denso on my Trailblazer as it was cheaper than AC Delco for literally the exact same part.

 

[Mooseman]

I went with NGK/NTK on my TB, helped my MPG.

 

[AzTruckGuy]

Best thing is to look up the part numbers on RockAuto and search them on Amazon. They have better pictures of the parts, including the connector and have found them to be a bit more accurate.

Cross checked Rock Auto before and the info I posted is correct on Amazon

I went with NGK/NTK on my TB, helped my MPG.

Oh here we go again lol How so? So far I am convinced the only way to get better MPG on the TB is the lighten it up "big time"

 

[smt 59]

I believe that somewhere on this site it is recommended to use the OEM sensor from the dealer, I went with the recommendation and had no issues replacing it and better gas mileage after it was in.

 

[AzTruckGuy]

I believe that somewhere on this site it is recommended to use the OEM sensor from the dealer, I went with the recommendation and had no issues replacing it and better gas mileage after it was in.

All of the sensors posted are OEM I am learning owning the Trailblazer that the stealership is just that and Ac Delco is not always Ac Delco...

 

[Mooseman]

ACDelco doesn't produce most, if not all, of its parts. Suspension and brake parts seem to be Raybestos, O2 sensors possibly NGK, oil filters definitely by Champion Labs, their lubes possibly by Shell and from what I can tell, their electrical and electronics by Delphi, including fuel pumps. Hell, even their spark plugs are probably made by NGK.

But that's not to say that ACDelco parts are the same as their original manufacturer's as they may be made to their specifications, or may be the same. We don't know for sure. All we have are our experiences. NGK O2 sensors seem to be good on this platform. Have heard that Bosch is not.

I think it's safe to say the NGK O2 sensors are safe, along with ACDelco.

 

[AzTruckGuy]

Well finally got my amazon gift cards in, ended up ordering all my parts for the Trailblazer including paying $12 for downstream used (like new) sensor and $32 for the (new) upstream sensor...those are some great deals

 

[Mooseman]

Dis you have any trouble with the downstream? It seldom needs to be replaced.

 

[AzTruckGuy]

Dis you have any trouble with the downstream? It seldom needs to be replaced.

Yeah I read that too but $12.47 for a brand new one and I'm at100k miles...cheap insurance

 

[AzTruckGuy]

,

This is a good reason to replace the downstream sensor even it doesn't fail, I am comparing the new downstream sensor vs my old upstream sensor, it has seen better days. I am sure thats the original sensor I am sure its the same for the downstream when I take it off, Wondering if I'll gain 1MPG? So I can test it with the upstream sensor out right? Drive around and see if I get any power gains which would mean I have a clogged cat?

 

[Mooseman]

Yes, that's the way to test. Better way would be a backpressure test but that will do.

 

[AzTruckGuy]

Oh man tried to remove the downstream sensor its stuck, so I drove to Walmart to get some blaster and the Traliblazer was in rice mode ha ha yeah its not clogged didnt feel more power, did feel more sluggish though the 1st gears and 2nd after that it leveled out

 

[AzTruckGuy]

Oh man that downstream sensor was a b!tch to get out, but I did it and I am glad I changed it. Almost stripped the threads because it wouldn't budge, so even though this sensor doesn't fail often, when I am trying to up my MPG, its a small price to pay. Now I am wondering about the exhaust system, I think the Trailblazer makes me want to spend money, its fun but I need to just fix the stuff that I bought. This is the only time I miss the rake on the Trailblazer, had it been there I would have had more room to work around the sensor, good thing the tranny pan has enough room to work when I change the fluid out.

 

[Mooseman]

The downstream sensor will do absolutely nothing for your MPG. All it does is tell the PCM that the cat is working.

 

[AzTruckGuy]

So did I get the Gen 2 sensor? Compared to my original sensor the new one is more robust and seems to not have the notches that the old one has? I looked it up and its the upstream sensor.

 

[Mooseman]

Probably an improved model or they changed their supplier.

 

[AzTruckGuy]

Mooseman you're right its a changed supplier. Ac Delco part#213-1551 I just came back from a drive and the Trailblazer felt so smooth, but then again I cleaned out the throttle body and disconnected the battery for 5hrs to reset the PCM. This sensor sticks out a lot more then the original but it diff more robust in design and quality.