[Dysan911]

Hey guys,

I could really use some help with this!. I am completely at a loss as to what to do next!.

I've had an AEM A/F gauge for a few months and it works great no issues. Suddenly one day on my way into work. Just a normal commute the gauge went over to 4 dashes FULL LEAN. It stayed that way for the remainder trip to work with an occasional flash of reading normal A/F.

I called AEM and they are diagnosing my gauge but I bought a brand new kit only to find it does the exact same thing.

I replaced the WB sensor, Ran the new harness under the car up into the drivers side just to bypass the other harness I have zip tied down underhood. I also tested with the new power harness direct to battery. Ground wire is solid.

I topped off my battery lastnight just to make sure it wasn't a factor.

All of these things. A brand new gauge, New sensor, new harness and it still does it. After you start the car it just usually idles at FULL LEAN 20:1 or higher. 4 DASHES. While idling occasionally you'll see a little life where it momentarily will read 14.5ish and then swing all the way lean and go back to 4 dashes.

I really don't like the idea that I can no longer monitor A/F but at this point I honestly don't know what else to do.

Here's a video. Towards the end you'll see it goes full lean. It just pretty much stays like that most of the time now.

https://youtu.be/I36M9w8sQWg

[JANNETTYRACING]

Log the car with your HPtuners to see if you have something going on with the fuel system.

You also may have developed an exhaust leak right near or before the sensor which it will pick up Oxygen.

[Dysan911]

Originally Posted by JANNETTYRACING

Log the car with your HPtuners to see if you have something going on with the fuel system.

You also may have developed an exhaust leak right near or before the sensor which it will pick up Oxygen.

I would love too but doesn't the HPTuners piggy back off the very same Wideband so if it's reporting lean like that won't the logs show that as well?

Car idles and drives fine fwiw other than 20:1 reporting from the A/F gauge.

I just pulled all my plugs. Other than looking a little rich none of them seem to be a problem. for the heck of it I put back my 6509s. It didn't help though.

I am at a complete loss on what I can do from here.

[JANNETTYRACING]

Originally Posted by Dysan911

I would love too but doesn't the HPTuners piggy back off the very same Wideband so if it's reporting lean like that won't the logs show that as well?

Car idles and drives fine fwiw other than 20:1 reporting from the A/F gauge.

I just pulled all my plugs. Other than looking a little rich none of them seem to be a problem. for the heck of it I put back my 6509s. It didn't help though.

I am at a complete loss on what I can do from here.

What I want to see is your narrow band sensors ( STFT and LTFT) and what they are saying so you can eliminate any actual running issues.

I would also suggest you thoroughly test your power and ground circuits feeding your wide band.

Ted.

[KingLT1]

Originally Posted by Dysan911

I would love too but doesn't the HPTuners piggy back off the very same Wideband so if it's reporting lean like that won't the logs show that as well?

Car idles and drives fine fwiw other than 20:1 reporting from the A/F gauge.

I just pulled all my plugs. Other than looking a little rich none of them seem to be a problem. for the heck of it I put back my 6509s. It didn't help though.

I am at a complete loss on what I can do from here.

There is a lot more to log then just the wideband. Wideband sensors are not end all be all for information. They can give erroneous numbers, but the tuner needs to correlate all data from a list of PID's that you log in order to make sure everything is working as intended. Looking at the Narrow band o2's and Fuel trims would be the first place I start to see if the wideband is acting up or is it actually letting you know that there is a problem elsewhere.

[Dysan911]

Ok I sent a log file and Ted confirmed it's 100% the gauge / wiring. That the tune is fine.

Thanks for checking that Ted!.

I'm going to pull my hair out trying to figure out the problem.

[JANNETTYRACING]

We have a saying the the auto industry, It's Always Grounds.

[Dysan911]

I tried a direct connection to the Positive terminal and Negative terminal. Same issue.

I grabbed a battery from a different car. Same issue.

Two different gauges,.. 2 different WB/Power harness and the issue doesn't change.

[JANNETTYRACING]

Originally Posted by Dysan911

I tried a direct connection to the Positive terminal and Negative terminal. Same issue.

I grabbed a battery from a different car. Same issue.

Two different gauges,.. 2 different WB/Power harness and the issue doesn't change.

Have you checked your exhaust system for leaks near the sensor

[Dysan911]

Originally Posted by JANNETTYRACING

Have you checked your exhaust system for leaks near the sensor

Yes. Its all good there.

[JANNETTYRACING]

Originally Posted by Dysan911

Yes. Its all good there.

Even a pin hold near the wide band O2 sensor can do this as there are both positive and negative pressures in the exhaust stream.

[Dysan911]

Originally Posted by JANNETTYRACING

Even a pin hold near the wide band O2 sensor can do this as there are both positive and negative pressures in the exhaust stream.

Not a flaw in these ARH's.

[Dysan911]

AEM had me do a free air calibration and both sensors FAILED.

I have a theory. Since the new sensor worked briefly. I think something with the old harness is grounding and frying the sensor.

Im going to get another sensor. I have removed the old WB Harness completely and hoping the new sensor plugged into the NEW harness will resolve this issue.

[Dysan911]

FWIW.. I got the new AEM Kit. Went over every header bolt and exhaust clamp. Managed to tighten everything ever so slightly. Ran all new wiring and and soldered every connection. Probably spent a good 4 hours on the car taking my time running the wiring, zip tieing everything in nice and secure and away from the headers, then once inside the car routing the harness away from the pedals, etc. I tapped power from the Cig Lighter in the center console so the gauge comes on with KEY ON and starts heating.

So far it's back to working like a champ!.