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To Wide band or not to wide band


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Yes, I recommend getting a wide band. The stock O2 sensor is not sufficiently accurate at the end of its range to tune your car properly for a custom tune. Also, the wide band is placed in the downpipe, post turbo where back-pressure does not affect the readings as much and it will be "averaging" the AFR from all cylinders whereas the stock O2 is looking at just one bank.

The off the shelf (OTS) tunes from the Cobb access port were developed to support "stages" of Cobb add-ons. That was the beauty of their system. You bought their downpipe, uppipe, intake, load the Stage 2 + OTS and you had a tune to support it. In reality though, you won't get the most out of it because every car will tune a little differently. This is mainly due to the response of your fueling system and integrity of your intake (pre and post turbo). When the cars were new, this was probably more true, but these cars have aged differently at this point. So, the best tune is a custom tune from a trusted Subaru tuner.

With the cars as old as they are now, it is extremely likely that there will be some issues with your fueling or intake from degradation of vacuum lines, breather hoses, air leaks, fuel pump output, fuel filter, gasket leaks, etc. They may not be horrendous problems, but they will likely be enough that an OTS tune won't be the best thing to use at this point because these small things add up to make your car run somewhat "uniquely".

So, my recommendation is to get a wide band and find a really good tuner so that your car can be tuned correctly and safely.

But even before that, make a really good assessment of your engine (compression, leakdown, look for gasket leaks), intake (check for leaks everywhere especially at the turbo inlet hose where it connects to the turbo and then do a smoke leak test and pressurize intake tract to no more than 5 psi to look for leaks), and fueling (replace the in-tank fuel filter and maybe pump as a preventative measure while you are at it). Check all breather hoses and vacuum lines, especially anything connected to the intake manifold, turbo inlet pipe, and bypass valve pipes since some will likely brittle by now and especially check the "blue tee", check the condition of your turbo and its supporting cooling and oiling lines (the oil return line under the turbo is prone to degrading and read up on the banjo bolt oil line filters on this forum).

 

 

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Yes, I recommend getting a wide band. The stock O2 sensor is not sufficiently accurate at the end of its range to tune your car properly for a custom tune. Also, the wide band is placed in the downpipe, post turbo where back-pressure does not affect the readings as much and it will be "averaging" the AFR from all cylinders whereas the stock O2 is looking at just one bank.

The off the shelf (OTS) tunes from the Cobb access port were developed to support "stages" of Cobb add-ons. That was the beauty of their system. You bought their downpipe, uppipe, intake, load the Stage 2 + OTS and you had a tune to support it. In reality though, you won't get the most out of it because every car will tune a little differently. This is mainly due to the response of your fueling system and integrity of your intake (pre and post turbo). When the cars were new, this was probably more true, but these cars have aged differently at this point. So, the best tune is a custom tune from a trusted Subaru tuner.

With the cars as old as they are now, it is extremely likely that there will be some issues with your fueling or intake from degradation of vacuum lines, breather hoses, air leaks, fuel pump output, fuel filter, gasket leaks, etc. They may not be horrendous problems, but they will likely be enough that an OTS tune won't be the best thing to use at this point because these small things add up to make your car run somewhat "uniquely".

So, my recommendation is to get a wide band and find a really good tuner so that your car can be tuned correctly and safely.

But even before that, make a really good assessment of your engine (compression, leakdown, look for gasket leaks), intake (check for leaks everywhere especially at the turbo inlet hose where it connects to the turbo and then do a smoke leak test and pressurize intake tract to no more than 5 psi to look for leaks), and fueling (replace the in-tank fuel filter and maybe pump as a preventative measure while you are at it). Check all breather hoses and vacuum lines, especially anything connected to the intake manifold, turbo inlet pipe, and bypass valve pipes since some will likely brittle by now and especially check the "blue tee", check the condition of your turbo and its supporting cooling and oiling lines (the oil return line under the turbo is prone to degrading and read up on the banjo bolt oil line filters on this forum).

 

 

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I couldn't agree with this any more. A simple compression check would have saved me thousands of dollars and altered many of my choices.

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That's a question for your tuner. My suggestion is yes.

 

100% agree. Some tuners re-scale the stock 02 sensor to be more accurate. I don't have a wideband and I'm flex fuel tuned with no issues.

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Yes, I recommend getting a wide band. The stock O2 sensor is not sufficiently accurate at the end of its range to tune your car properly for a custom tune. Also, the wide band is placed in the downpipe, post turbo where back-pressure does not affect the readings as much and it will be "averaging" the AFR from all cylinders whereas the stock O2 is looking at just one bank.

The off the shelf (OTS) tunes from the Cobb access port were developed to support "stages" of Cobb add-ons. That was the beauty of their system. You bought their downpipe, uppipe, intake, load the Stage 2 + OTS and you had a tune to support it. In reality though, you won't get the most out of it because every car will tune a little differently. This is mainly due to the response of your fueling system and integrity of your intake (pre and post turbo). When the cars were new, this was probably more true, but these cars have aged differently at this point. So, the best tune is a custom tune from a trusted Subaru tuner.

With the cars as old as they are now, it is extremely likely that there will be some issues with your fueling or intake from degradation of vacuum lines, breather hoses, air leaks, fuel pump output, fuel filter, gasket leaks, etc. They may not be horrendous problems, but they will likely be enough that an OTS tune won't be the best thing to use at this point because these small things add up to make your car run somewhat "uniquely".

So, my recommendation is to get a wide band and find a really good tuner so that your car can be tuned correctly and safely.

But even before that, make a really good assessment of your engine (compression, leakdown, look for gasket leaks), intake (check for leaks everywhere especially at the turbo inlet hose where it connects to the turbo and then do a smoke leak test and pressurize intake tract to no more than 5 psi to look for leaks), and fueling (replace the in-tank fuel filter and maybe pump as a preventative measure while you are at it). Check all breather hoses and vacuum lines, especially anything connected to the intake manifold, turbo inlet pipe, and bypass valve pipes since some will likely brittle by now and especially check the "blue tee", check the condition of your turbo and its supporting cooling and oiling lines (the oil return line under the turbo is prone to degrading and read up on the banjo bolt oil line filters on this forum).

 

 

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Good looking Salty!!! I already had a compression/leak down done and they are...

Cyl1 -150

Cyl2 -140

Cyl3 -140

Cyl4 -145..... does this say don't tune??? I was told they were good....And I will deff go threw all the things you said as a check list....thanks again

 

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Since we're on the topic, what do people prefer? I've been debating between the AEM UEGO and the PLX Systems SM-AFR Wideband DM-6 Gauge Combo (Gen4). which is easier to install? I will be having Dave from Cryotune performance dyno tune my car next month.
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I suppose I should extend my answer... your tuner will use a wideband to tune your car (unless they are completely incompetent). If you don't have a spot for one in your exhaust, they'll just mount it at the end of the tailpipe and tune with that.

 

You don't necessarily need one for daily after the car is tuned, but it's always a good bet if you can monitor/log it. But if your tuner is worth their salt (which Dave @ Cryo is), you shouldn't need to monitor it on a day-to-day once the tune is complete.

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well, I'm trying to set up Dave for success. I'd rather have a properly installed wideband for him to use while he tunes, rather than sticking it up my cars ass. Since we're here, what's a good catless downpipe to go with that already has the wideband bung on it? (05 LGT Wagon 5EAT)
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thats about the worst option you have. especially if you have a cat.

 

It's not ideal, but you can still tune most everything with a tailpipe wideband. The readings will be a bit leaner than what you'd see pre-cat so the tuner will have to target slightly different AFRs, and there will be more delay in the AFR readings so it becomes harder to tune transients like tip-in enrichment, etc. But other than that, there's no real difference.

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^^^^^my next question...

 

 

 

You also have the LC-2 option from Innovate Motorsports.

 

If I did it again, I would go for the AEM Uego because their calibration procedure is easier. You don't have to remove the sensor from your exhaust port and into "free air" to calibrate it. You just leave it installed. They claim, at least, that their system calibrates fine that way. It's a little bit of a pain to remove the sensor from your downpipe.

 

I know that Dave has mentioned liking the PLX too.

 

Great compression numbers : ) I hope you were able to do a leakdown test as well.

 

 

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I saw that. I'm looking for a catless DP though. I'd much rather find a used one since I'm going to be paying good money for the tune as well. I have a good job, but I don't have that kind of money burning a hole in pocket.

Why catless? Like the smell?

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+1 on AEM UEGO. AEM's in my experience tend to last longer, plus I got sick and tired of the yearly open air calibration requirements for MTX-L's. One thing I read against home open air calibrations is, it's never going to be as accurate as a in lab calibrated sensor.

 

 

the smell vs the no hp gains I would take the cat all day.

 

While I do run a cat myself, they still create backpressure. Even the 300cel high flow cat in my GS downpipe measured 3.5psi of backpressure right behind the turbo, and GS cat's are all the way back at the end of the downpipe.

 

After the cat, the stock exhaust measured 4psi of backpressure. My custom 3" exhaust with a bored out 3" 2007 STI muffler measured 1-1.5psi of backpressure.

 

Long story short, if I went catless on stock exhaust, I would have removed more backpressure then doing a full 3" exhaust :lol:. Not advocating for going catless, just point out that they are still a pretty major restriction in the exhaust system.

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

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