AEM air fuel ratio Gauge issue help ?

[furg69]

I have a AEM digital Air fuel ratio gauge installed on my supercharged Nytro. it was showing between 11.5 and 13.5 depending on what speed I was running. The issue is yesterday it started showing 14-15-16 even flashed 17 and a few straight - - - dashed on the screen. im thinking it must be a gauge issue and not the sled. I sure hope it didn't run that lean. anyone have any pointers or know what could be the issue, maybe it is my GEMS controller but if the sled really reached 17 I cant see it being drivable after a couple miles. wouldn't the motor be toast if I did actually reach a value of 17

 

[kinger]

Its the O2 sensor or you have a exhaust leak (ie crack) I cant get a 02 sensor to last more then 1 season.

 

[edge_232]

The higher the number the richer it is not lean. At idle & even gradual acceleration mine will be --- your O2 sensor may be toast. I know race fuel is hard on them.

 

[Srxspec]

The higher the number the LEANER it is!

9 on the air/fuel ratio gauge is super rich!

17 on the air/fuel ratio is super lean!

Generally speaking, if you get above 14 or 15 on the gauge, the sled will actually stumble or not run right.

 

[edge_232]

Sorry, I was #*$&@ backwards then in my thinking. I'll to re verify the gauge on my sled but I know there is no stumbling what's so ever on it & it runs spot on.

 

[DC5]

The higher the number the richer it is not lean. At idle & even gradual acceleration mine will be --- your O2 sensor may be toast. I know race fuel is hard on them.

If your getting the 3 lines at idle and low throttle but it works everywhere else you likely have an exhaust leak.

 

[edge_232]

I never noticed an exhaust leak when I changed to the copper donuts over the summer. I never heard the typical exhaust tick from a leak or seen any of the normal exhaust stains you get from a leak either. Not sure what might be going on?

 

[edge_232]

Might be my O2 sensor possibly?

 

[DC5]

Could be, try swapping it but it should give you good readings all the time, like Allen said if it is lean enough to show the 3 dashes it would not run right

 

[kopenytro]

Furg69,
It is your O2 sensor. I had the exact same problem with my gauge early this winter.
Replaced the sensor and gauge worked fine for the rest of the year.

Did some research last summer trying to determine the problem and found out the following fun facts:
(BTW - I know everything you read on the internet is not true, the gospel or can be interpreted differently than the originator intended.)

1) Bosch sensors are more prone to failure then NGK brand.
- I read on multiple forums that there is a NGK exact replacement (plug and play) for the Bosch unit.
- The NGK is what I am running now and have had no issues since.
- Before you ask, I do not remember the NGK part number, however the TY4 search engine and Google are your friends.

2) Bosch sensors are not a fan of race fuel and/or octane booster.
- I burnt out 2 Bosch running race gas or booster. Switched to the NGK and no issues all of this season.

3) You can try and clean the end of your old sensor and you might have short term success.
- However if your gauge starts out with ok idle readings then rises to the --- fairly quickly (with in 10-20 second) save yourself the headache and just replace the sensor.

4) Use a little dielectrical grease on the plug and play connectors
- Cheap insurance

5) Fun costs money.
- Reliable fun costs more money.

Hope that helps and good luck.
Kope.

PS: Anyone have a Garrett Gt 2554r laying around they would want to get rid of?

 

[mbarryracing]

For my AEM 30-4100 AFR gauge I switched over from the Bosch to the NTK 24320 and it's lasted 2 seasons now and still working strong. The original 0258007206 bosch sensor would only last a few weeks, even on straight pump gas.It would always start getting lazy then stop cycling all together. Not sure if it was the heat or rich AFR that did it in. Leaded Race fuel would wax it the same day.