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Wideband vs Cobb AP

11K views 3 replies 4 participants last post by  MainFrame 
#1 ·
Hey guys, Im going to apologize in advance for this question, it seems like a newbie question but it's something I can't really find a straight answer on. And when i talked to various tuners/shopowners about it, they all had mixed responses.

The question is, is a wideband monitoring gauge/system such an Innovative or AEM really necessary when you have a Cobb AP? I'm wondering this because obviously the AEM and comparable units are a wideband sensor, and from my understanding the Cobb AP uses the stock narrowband sensor for it's AP data display. When my car was tuned it had the tailpipe sensor attached, but would you personally install a wideband gauge if you have an AP already, and why? I will be getting my car retuned here in the future and am wondering what the better option is both for tuning on the dyno, and for keeping tabs on your motor's health after the tune when you are going about your daily life.

The wideband is $150-300 extra depending, so I'm wondering if it is worth the cost.

Thanks again, Wreckingball
 
#2 ·
I'm not entirely sure how the AP calculates AFR, but I do know that the way it calculates is rather inaccurate. Narrowband o2 sensors, which is what the AP uses, are only built to determine 3 things. Those three things are whether the mixture is Rich, Stoich or Lean. That is all. That's why it's called a narrow band, because it has a narrow window of what it can do.

Wideband 02 sensors are extremely accurate and are required to have a professional tune. Some shops can provide their own that they clip to the tail pipe. But having one installed will be preferred by almost all tuners. Anyhow, wideband 02 sensors can tell you the exact A/F within a range that you will never even really need to use in it's entirety.

So essentially, data logging A/F through the Cobb AP is pretty much useless for any conditions other than idle. A wideband is just useful to have if you enjoy constantly monitoring your A/F, or if you ever wish to have a professional tune.
 
#3 ·
Wideband O2 is necessary for tuning.

The OEM front O2 sensor is capable of wideband AFR judgement, with one critical problem: the placement.

OEM front O2 sensor is located in the header between the heads and turbo. Under normal cruising, judgement using this sensor is adequate. As the load increases and the turbo starts to build boost, the manifold pressure will rise above 50 PSI. An O2 sensor reading is affected by pressure, so it becomes inadequate for reading AFRs accurately.

TL;DR the AP can't be used for more than flashing useless numbers in your face.

Sent from my SAMSUNG-SM-G890A using Tapatalk
 
#4 ·
Under boost, where you really need it, info that you get on the AP from the OEM sensor is virtually useless. If you have an AP and were looking to install ONE aftermarket gauge to keep tabs on how your car is running, WBO2 would be the gauge to get, hands down. It's a requirement for dialing in a good tune, but perhaps not totally necessary beyond that. Personally, I would get one.
 
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