Better wideband placement; front or rear o2

[Denji]

Okay, this has been covered before, i know because i searched. Typically everyone says "follow the wideband instructions". Well i don't have a wideband yet. So the question is, do all the wideband sensors have the same rules for placement? If not, is front or rear o2 stock location better? If they are different, and one location is better, i will base my purchase off of that criteria. Otherwise, I will purchase a wideband AEM UEGO for the price and so that i can monitor fuel at all times via the gauge even when im not linked to a laptop.

I can use either stock location easily becuase I purchased ECUplus recently and it has front or rear o2 simulator capabilities.

Thanks- Brandon

 

[turbosax2]

Are you against having the new bung for the sensor welded in? Ideally, you wouldn't use either of the stock locations, you would place the new bung wherever the instructions say to put it and what location is most convenient for you. On my brother's car, we put the bung between the flex section and the cat.

 

[Denji]

Are you against having the new bung for the sensor welded in? Ideally, you wouldn't use either of the stock locations, you would place the new bung wherever the instructions say to put it and what location is most convenient for you. On my brother's car, we put the bung between the flex section and the cat.

No, I'm not necessarily against it. I'd have to be convinced it provided a benefit that was worth the cost and trouble of not using the ECUplus simulators, which are extremely convenient and free (well already paid for).

 

[DGajre777]

Use the rear o2 placement if you don't have a cat, the wideband o2 sensor needs to be atleast 24" from the turbo, last time I read the instructions.

While ECUPlus simulates the sensor part, you may still need to get a heater element if you take out your rear o2 sensor on the 2G to avoid a CEL.

 

[turbosax2]

I'm not familiar with ECU+ so I don't know what the simulators are like that you're talking about. If you don't have a cat then putting the sensor in the rear location would be ok. If you do have a cat, then you cannot place the sensor in the rear location as the cat will mess with the readings. Although many people have successfully run their sensors in the front location, I'm not sure that I would want to risk ruining an expensive sensor just to save a few bucks on welding costs.

 

[tkelly27]

isn't the rear one post cat? If so, you want it to be pre-cat.

The front one is too close to the turbo, you'll burn up the sensor.

Getting a bung put on should be no more than $20 at any muffler shop. Cheap insurance to protect your $80 sensor and your engine.

 

[DGajre777]

isn't the rear one post cat? If so, you want it to be pre-cat.

The front one is too close to the turbo, you'll burn up the sensor.

Getting a bung put on should be no more than $20 at any muffler shop. Cheap insurance to protect your $80 sensor and your engine.

Yup, what ^^^ said.

You can put the wideband in the rear o2 hole if you run a test pipe or a cat eliminator downpipe.

The other option is to put a bolt in the front o2 hole, if you don't want the factory front o2, have a o2 bung welded about 24" from the turbo and put the wideband in that.

 

[2gGSX]

The statement that the wideband must not be placed behind a catalytic converter is correct.

While the sensor is not SUPPOSED to be subjected to temperatures above 850*C, many people have ran the sensor in the stock front location without any issues. In my opinion, a position in front of the flex section may be an ideal compromise--it is further away than the stock front location which will control the temperatures, but in front of the flex section (which, in my opinion, is very likely to have a leak).

 

[Denji]

Well, thats unfortunate. What is the point of a front o2 sensor simulator if you shouldnt use it? . Okay, well i do have a cat so that is not an option. I suppose to be safe i'll just get another bung welded. Disappointing...

 

[oldman]

While the sensor is not SUPPOSED to be subjected to temperatures above 850*C, many people have ran the sensor in the stock front location without any issues. In my opinion, a position in front of the flex section may be an ideal compromise--it is further away than the stock front location which will control the temperatures, but in front of the flex section (which, in my opinion, is very likely to have a leak).

Agreed, have the sensor pointing up at the gap between your block and the firewall.

 

[99gst_racer]

Agreed, have the sensor pointing up at the gap between your block and the firewall.

^^^ This is also where my wideband sensor's bung was welded. Almost 2 years of heat abuse and leaded fuel, and she's still ticking.

 

[oldman]

Mine doesn't tick at all, you might want to get that checked out.

 

[2gGSX]

One note--according to the AEM (or was it PLX) install guide, the sensor should be pointing slightly downwards (roughly 15 degrees to the horizontal) in order to avoid fuel being pooled onto it during the cold start enrichment cycle.

I don't really think this should be a problem, but who knows?

 

[oldman]

One note--according to the AEM (or was it PLX) install guide, the sensor should be pointing slightly downwards (roughly 15 degrees to the horizontal) in order to avoid fuel being pooled onto it during the cold start enrichment cycle.

I don't really think this should be a problem, but who knows?

According to the LC1 manual,

Do not install the bung below the 3 or 9 o'clock position. Condensation can form in the exhaust pipe and permanently damage the sensor. 6 o'clock is the absolute worst position to mount the sensor.

 

[2gGSX]

AEM-30-400-AFR-UEGO-instructions.pdf at http://tunertools.com/prodimages/AEM/manual/AEM-30-4100-AFR-UEGO-instructions.pdf

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[JayRolla]

Whats wrong with placing it in the front. My mechanic has done this many of times with no problem.

 

[oldman]

Whats wrong with placing it in the front. My mechanic has done this many of times with no problem.

High temperature (> 900*F) = shorter life. It may work fine but for how long is the question, I would at least install a copper heatsink.

2gGSX, sounds like both LC1 and AEM are saying the same thing.

 

[steve]

Whats wrong with placing it in the front. My mechanic has done this many of times with no problem.

As already explained in this thread. It's too hot and shortens the life of the sensor.

 

[2gGSX]

High temperature (> 900*F) = shorter life. It may work fine but for how long is the question, I would at least install a copper heatsink.

2gGSX, sounds like both LC1 and AEM are saying the same thing.

Man I completely missed the "Do not install" part of your post. English as a second language =

 

[bmoha2]

At first I kinda blew it off as goofy but I have learned a few things. I never knew there was any problem with mounting a wideband in the front stock o2 sensor position but I'm the only one of my friends that own a turbo dsm. My Honda friends have never had a problem running a wideband in the front o2 sensor position but of course none of them are turbo'd!

 

[oldman]

Man I completely missed the "Do not install" part of your post. English as a second language =

Damn foreigners.

 

[JayRolla]

As already explained in this thread. It's too hot and shortens the life of the sensor.

I already knew this just thought there was some type of problem with the reading. I know someone running it in the front for about 2 years so I dont see the issue.

 

[2gGSX]

We all also know of people who ran 10's with small injectors, but that doesn't make it the best way of doing things. The point is what works for one person may not work for everyone, which is why manufacturers give their recommendations on what to do.

 

[Denji]

At first I kinda blew it off as goofy but I have learned a few things. I never knew there was any problem with mounting a wideband in the front stock o2 sensor position but I'm the only one of my friends that own a turbo dsm. My Honda friends have never had a problem running a wideband in the front o2 sensor position but of course none of them are turbo'd!

I am a goofy kinda guy. But i'm also the kind of guy that doesn't like to act like i know something that i don't know. Anyhow, I'm really glad i asked because i was going to place it in the front o2 sensor stock position but not now.

I'm trying to learn how to read knock and stuff on my ecu+ logs, but i'm having trouble with that too. This whole tuning/logging thing is new to me.