RANT!!! PSA for anybody buying an aem wideband

96pushrod

I think they're a little easier to get off
5 Year Member
May 15, 2018
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So I usually run an aem wideband in most everything we do, usually a 30-0300 or a 30-4110. The past couple years I’ve seen the supplied sensors fail 3 different times. Twice on my cars, and once on a ls truck we built in the shop. Each time they’ve been replaced with a parts store Bosch 17025 and they work great for years.

So this last time, I had a aem gauge actually just quit working. I’d had it for years so I just replaced it with another. I reused the 4.9 sensor (the parts store one) since it worked well and had the supplied aem 4.9 in the box. About a month ago, that parts store 4.9 failed (which it had lasted a few years) so I swapped it out with the supplied aem sensor. That sensor lasted all but 2 hrs and then quit on me.

So naturally I was pissed and I emailed aem about the failure. I called them out that this had happened several times, and only with their supplied sensor. They mailed me a replacement one. Which lead me to what I discovered today.

I believe they’re shipping knock off ones in some of their kits.

Every single aem wideband we’ve ever purchased had came directly from summit racing (or atech, the summit wholesaler), I have POs for all of them.

If you buy an aem sensor, make sure it looks like this, which was the replacement they sent me:


2D0A229F-C2C8-43EE-BB2F-972B94C0E7E3.jpeg


And not this, which was the one that came with the 30-0300 kit:

A15D7642-D3BA-4860-95BB-25F2542E115D.jpeg


Let me know what you guys think. Anyone else seen this?
 
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Good to know, I was looking to buy a wideband for my cts-v to get it tuned. Do you happen to have extra gauges laying around before I buy new?
 
This is interesting, I have an AEM gauge from a few years ago that was bought at Summit Racing. Here's what it came with.
20210415_195905.jpg
20210415_195922.jpg


Kind of looks like a no name with a Bosch sticker on the wire, and none of the numbers match. It's worked good for a couple of years now. I saved your picture for reference when this one dies on me. Thanks.
 
Good to know, I was looking to buy a wideband for my cts-v to get it tuned. Do you happen to have extra gauges laying around before I buy new?
I don’t have any extras. I still like the aem widebands, and maybe they got a garbage batch of sensors from a supplier. Who knows. I know the replacement sensor they sent me is a legit Bosch 4.9, so I’m sure it’ll be good.

I actually did email Bosch with a picture of the one that failed, and the rep said it appeared to be fake, but also said it’s tough to come to a for sure conclusion. He also mentioned there isn’t always the Bosch logo on the body, but it’s not as common since these are usually ordered in bulk from major auto manufacturers, so they can have their own part number on them. He also said he’s not used to seeing them without the purplish heat mark either.


LX - that’s actually a similar number that I’ve seen on 4.9 sensors before.
 
This is interesting, I have an AEM gauge from a few years ago that was bought at Summit Racing. Here's what it came with.
20210415_195905.jpg
20210415_195922.jpg


Kind of looks like a no name with a Bosch sticker on the wire, and none of the numbers match. It's worked good for a couple of years now. I saved your picture for reference when this one dies on me. Thanks.


Hi AEM Electronics here – this thread was brought to our attention and we wanted to chime in. All AEM Widebands come with Bosch sensors. Over the past few years there have been gaps in supply from Bosch which forces us to source our sensors on the global market where there are times the sensors come from Bosch Distributors with different color heat shielding (blue or black) on the harness or where the o2 sensor body is buffed…and in some cases the o2 harness length varies. But, the sensors are all confirmed to be OEM Bosch.

I noticed that you mentioned purchasing from Summit/Atech who is a good direct customer of ours, so the concern of those gauges or sensors being counterfeit should be dismissed (note: our gauges and some of our other products have been counterfeited please visit here for more information): https://www.aemelectronics.com/dealer/beware-counterfeit-aem-electronics

I’m not sure what’s going on in this case with the shortened life of the sensor (any major tune changes or fuel?), but if you like, we can get your gauge back to us for testing to confirm all is working to spec. We will waive any inspection fees…and just a reminder, if you do choose to do so, please pull the good o2 sensor out and install a bad sensor or o2 sensor bung plug. Leaving in a good sensor while not powered up with almost certainly foul the sensor due to the heater element not functioning while the gauge is out.
 
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Hi AEM Electronics here – this thread was brought to our attention and we wanted to chime in. All AEM Widebands come with Bosch sensors. Over the past few years there have been gaps in supply from Bosch which forces us to source our sensors on the global market where there are times the sensors come from Bosch Distributors with different color heat shielding (blue or black) on the harness or where the o2 sensor body is buffed…and in some cases the o2 harness length varies. But, the sensors are all confirmed to be OEM Bosch.

I noticed that you mentioned purchasing from Summit/Atech who is a good direct customer of ours, so the concern of those gauges or sensors being counterfeit should be dismissed (note: our gauges and some of our other products have been counterfeited please visit here for more information): https://www.aemelectronics.com/dealer/beware-counterfeit-aem-electronics

I’m not sure what’s going on in this case with the shortened life of the sensor (any major tune changes or fuel?), but if you like, we can get your gauge back to us for testing to confirm all is working to spec. We will waive any inspection fees…and just a reminder, if you do choose to do so, please pull the good o2 sensor out and install a bad sensor or o2 sensor bung plug. Leaving in a good sensor while not powered up with almost certainly foul the sensor due to the heater element not functioning while the gauge is out.
I’m glad you guys chimed in. The tune on the car has pretty much never changed, at least not in the last year and a half. Car has always been consistent and always just ran on regular unleaded gasoline

I’ve really never had any sort of issues with the gauge itself, just the sensors. I had one gauge fail, but it was after a couple years so I really didn’t care about that.

Doesn’t it seem odd somebody would buff off the only thing that actually identifies the sensor? Especially on a manufacturer where there is so many people making fakes.

If you guys want the old sensor back you’re welcome to it. I had just planned on tossing it in the garbage.

Anyways, this isn’t a “:leghump: aem” post or anything like that, because frankly I’ve always liked the products I’ve bought from you guys - and I’ll continue to do so. I just saw a trend and was curious what others have experienced.
 
I’m glad you guys chimed in. The tune on the car has pretty much never changed, at least not in the last year and a half. Car has always been consistent and always just ran on regular unleaded gasoline

I’ve really never had any sort of issues with the gauge itself, just the sensors. I had one gauge fail, but it was after a couple years so I really didn’t care about that.

Doesn’t it seem odd somebody would buff off the only thing that actually identifies the sensor? Especially on a manufacturer where there is so many people making fakes.

If you guys want the old sensor back you’re welcome to it. I had just planned on tossing it in the garbage.

Anyways, this isn’t a “:leghump: aem” post or anything like that, because frankly I’ve always liked the products I’ve bought from you guys - and I’ll continue to do so. I just saw a trend and was curious what others have experienced.
We appreciate your support! PM me with your email address and we will send you a call tag to ship the sensor. We would like to see it. As for the buffing, we agree that it is strange and can’t explain the “why”, but can say that “what” we put in our kits is OEM Bosch.
 
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LX - that’s actually a similar number that I’ve seen on 4.9 sensors before.
That's good to know.
Hi AEM Electronics here – this thread was brought to our attention and we wanted to chime in. All AEM Widebands come with Bosch sensors. Over the past few years there have been gaps in supply from Bosch which forces us to source our sensors on the global market where there are times the sensors come from Bosch Distributors with different color heat shielding (blue or black) on the harness or where the o2 sensor body is buffed…and in some cases the o2 harness length varies. But, the sensors are all confirmed to be OEM Bosch.

I noticed that you mentioned purchasing from Summit/Atech who is a good direct customer of ours, so the concern of those gauges or sensors being counterfeit should be dismissed (note: our gauges and some of our other products have been counterfeited please visit here for more information): https://www.aemelectronics.com/dealer/beware-counterfeit-aem-electronics

I’m not sure what’s going on in this case with the shortened life of the sensor (any major tune changes or fuel?), but if you like, we can get your gauge back to us for testing to confirm all is working to spec. We will waive any inspection fees…and just a reminder, if you do choose to do so, please pull the good o2 sensor out and install a bad sensor or o2 sensor bung plug. Leaving in a good sensor while not powered up with almost certainly foul the sensor due to the heater element not functioning while the gauge is out.
Only replying because you quoted my post. I used this current one for a couple of years with no problems, for tuning my truck. Currently, it's not installed in anything, kind of waiting for the next project.
 
We appreciate your support! PM me with your email address and we will send you a call tag to ship the sensor. We would like to see it. As for the buffing, we agree that it is strange and can’t explain the “why”, but can say that “what” we put in our kits is OEM Bosch.
I always used another manufacturer’s product over AEM on previous cars. My only problem with the other product was customer support. I’ll be switching to your product just because of your actions. Thank you.
 
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I just found this thread and wanted to mention I'm having the exact same problem.

Purchased an AEM 30-4110 wideband gauge with "Bosch" LSU4.9 sensor which does not have the Bosch logo/part number stamp.

I haven't even driven the vehicle yet and the o2 sensor is apparently already bad. Tunerstudio is reporting a completely unchanging & unrealistic lean o2 signal voltage while the engine is obviously running quite rich, and the AEM gauge just shows three dashes(off-the-scale indicator I guess?)

I ordered the AEM 30-4110 on Ebay from a seller named Boostprojects and I can't help but think this is a fake knockoff bosch o2 sensor. Why else would it not have the Bosch stampings, and why would it be dead already? I don't know if it's Boostprojects including fakes in their kit or if it's coming from AEM this way. I just hope the gauge is genuine... or are the Chinese making fake AEM's too?

I just placed an order for a known-genuine replacement Bosch 17025 so hopefully that solves my problem.
 

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Installed a 30-0300 wideband in a friend’s car about a year ago. It’s that blue convertible I did a v2 on and just got done doing hci on. A year in, and well under 2000 miles later of course the sensor takes a :poo:.

You’d think I’d quit buying the aem stuff, but the controller and gauge does work good. I contacted their cs, again, and since the sensor is more than 6 months old they won’t warranty it. Honestly it’s a shame they won’t just come out and admit the sensors they provided with these kits are **** from the get-go.

So anyways, another aem supplied wideband sensor goes in the trash.
 
I have some questions for you and this should help answer the question you have.....

On the set of wires where one of the wires goes to pin #27 on the ECU plug where did you put the ground wire its paired with?

FYI: I connected my ground wire the #27 wire is paired with to pin #40 on the ECU plug going to a clean ECU ground........Without a clean ECU ground for the #27 ECU input side the unit wont work as intended for very long..

The other question is kinda 3 parts...Did you check to make sure the sensor is mounted in the correct position in the pipe and in the right vacinity as far as length plus did you do a continuity test between the sensor body and the battery to make sure the sensor is grounded good?

Did you make sure the power you're using to power the unit is adequate?..My input power is being tapped from the 12v pin on the AM1 solenoid and grounded to the battery negative..

If the sensor is too far away or mounted wrong or not powered or grounded right it will cause failures too..

Good Luck
 
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I have some questions for you and this should help answer the question you have.....

On the set of wires where one of the wires goes to pin #27 on the ECU plug where did you put the ground wire its paired with?

FYI: I connected my ground wire the #27 wire is paired with to pin #40 on the ECU plug going to a clean ECU ground........Without a clean ECU ground for the #27 ECU input side the unit wont work as intended for very long..

The other question is kinda 3 parts...Did you check to make sure the sensor is mounted in the correct position in the pipe and in the right vacinity as far as length plus did you do a continuity test between the sensor body and the battery to make sure the sensor is grounded good?

Did you make sure the power you're using to power the unit is adequate?..My input power is being tapped from the 12v pin on the AM1 solenoid and grounded to the battery negative..

If the sensor is too far away or mounted wrong or not powered or grounded right it will cause failures too..

Good Luck
These aren’t on factory ecus, but yes they’re installed correctly. I have a dedicated bus bar for switched 12v power using a large relay, sensor heater ground is on chassis, signal return grounds to the dedicated sig return on ecu. It’s fairly straightforward.

Not like it really matters though, if the wideband signal return is grounded to a clean chassis ground, it’ll still work fine.

When the supplied aem sensors - that look exactly like the $40 ones on Amazon - last a few hrs, and the replacements all last for years, I’d venture to say it’s the supplied sensor that’s the issue.
 
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These aren’t on factory ecus, but yes they’re installed correctly. I have a dedicated bus bar for switched 12v power using a large relay, sensor heater ground is on chassis, signal return grounds to the dedicated sig return on ecu. It’s fairly straightforward.

Not like it really matters though, if the wideband signal return is grounded to a clean chassis ground, it’ll still work fine.

When the supplied aem sensors - that look exactly like the $40 ones on Amazon - last a few hrs, and the replacements all last for years, I’d venture to say it’s the supplied sensor that’s the issue.
I played this same game with an INNOVATE wideband as well. I don't believe that this is unique to AEM. Junk wideband sensors go back at least as far as my still fully operational LM-1. :D