Yea, it'll be something to look at when I pull stuff apart to change the spark plugs.

BTW... should I monitor AFR from the CAN bus data, or should I get an aftermarket gauge and sensor? If I can rely on the CAN bus data, then it'll save a lot of wiring work. I may get a digital multi gauge with ODB2 input.

I'd always trust an aftermarket wideband over the factory O2 sensors.

:iagree:

Get a wideband bro, there actually really easy to wire.

My wideband has help me diagnose 99% of my problems.

Also, test your vacuum, maybe you have a leak somewhere.

Thanks. So is better to get a wideband sensor and AFR gauge versus pulling AFR Bank1 and Bank2 using Cipher?

Yea, hopefully I can get a hold a smoke machine. I'll get it done after maintenance work.

Yes. Aftermarket AFR is better than trusting the numbers from Cipher

Do any of the 370z even have factory widebands? I remember a couple years of the 350z did for a minute, but then they ditched it.

If the factory o2 sensors are not widebands, the A/F reading anywhere about a half point away from stoich is worthless data.

My 2009 uses standard narrowband o2s.

Do some fuel logs but I can almost guarantee you that one or both of your gtm exhaust manifolds are Cracked causing a Rich condition.... Ask me how I know...

I was going to ask you the very same question after asking you about symptoms. :P Do you hear any high pitched whistling? I've been hearing the faint whistle for the past year, and it seems like it's on the passenger side. Evidently, it is the same one that has a minor oil leak, but not enough to drip. There's no blue smoke. The PCV hose and vacuum line to the throttle has oil residue as well. The driver side is clean. I can only imagine what it'll be like after removing the throttle bodies.

I'll have the exhaust manifolds checked the next time the car gets on a lift.

I remembered this being discussed at one time, and I thought that's what people concluded - that the cars come stock with widebands. I was just curious to see the wide band sensor parameters in Cipher. If that's the case, then I'll consider getting a sensor makeover at some point to go with the digital multi gauges from Zada Tech. Phew... gonna be pricey.

Just buy a digital Innovate. $180 and your set.

One for each side?

Look up EVAP diy smoke machine, you can make one for 10$.

Hook her up to a vacuum line, and watch for smoke :)

You can do that but I'd probably look for a single readout that will read both gauges. With the LC-1/2 you would have to run a second gauge. Most people just monitor one bank. I recommend bank 1 (passenger side) because it seems to run slightly leaner than bank 2. If you don't have the bung in either the downpipe or lead pipe just have a bung welded into the lead pipe of the FI exhaust. A muffler shop should be able to do that pretty quickly at a low cost.

Chuck - I can't recall off the top of my head, but where's your AFR O2 sensor located?

Edit - Innovate makes a single gauge dual wideband but I can't seem to find it any place but eBay for instock purchase so it might be discontinued.

http://www.innovatemotorsports.com/products/dlg1.php

This is the one I run LC-1 with the DB gauge

http://www.innovatemotorsports.com/products/db.php

Kosmic welded a new bung in one of the downpipes.

Before install. That's right.

DIG - I would recommend tapping the lead pipe on the FI exhaust over trying to tap the downpipe in the installed condition.