aem 30-4100 and ms1 gauges dont match

[danno16127]

my aem wideband gauge and the gauge in ts do not match. ive tried each wideband from the pull down menu, and none match. I know the values that came with my aem gauge as far as what volts equal what afrs, but how do I add those into ts? ive read about a "custom linear wideband" selection, but I do not have this. where can I imput these values so that my gauges match? thanks guys

[danno16127]

went to the newer ini file, got the custom linear option, imput my values, and its still off, by a lot. I emailed diyautotune and matt is helping me out thru email, just wondering if anyone else has had this problem and what you did to correct it, thanks!

[Nitroking]

I do have it. Fixed it by playing with the values on Custom Linear Wideband. I think the firmware needs an option for the very popular 30-4100.

[danno16127]

haha, do you think you could give up those values?

[Nitroking]

If I remembered them I would give it to you of course. It was in a client's car. I had forgot I did that trick, only to realize it when another customer's car had the same issue which I didn't have the time to deal with and finally tuned the whole VE Table manually.

Just trial and error it, you will find the sweet spot. Remember, you need to make it read correctly in the 13.5 to 15.5 range, you don't care about it outside of these limits. If you are accurate on 13.5-15.5 you are good to go for autotune and then closed loop lamda function. That's all the lamda is needed for.

[Nitroking]

I remembered what I had done to make it look the same at the AEM gauge and TS.

I simply grounded the AEM straight on the engine head instead of using the ms ground and it works like a charm!

Please give it a try and let me know if it has helped you.

Nick

[Nigep]

Mine are grounded correctly, but I`ve always had a discrepancy between the gauge and Tunerstudio.

Changed the AFR to a custom on as below and it works, reading is within 0.1 now

I couldn`t select `Custom Linear Wideband` in the EGO sensor selection, so had to create a new project, select it in there and import the rest of the setup from a previously saved project.

The newer AEM UEGO is linear by default, but has a backward compatibility mode for the non-linear output.
The documented linear output is 0-5V = 10:1-20:1 AFR.
But for some reason most users of the AEM UEGO with MS claim that does not match what they are seeing on the AEM gauge, so the linear formula used in TunerStudio and MegaTune is a slight deviation from that.

0V = 9.72:1
5V = 19.61:1

This is what users have found to match their gauge.

I don't have an AEM so I haven't verified it directly.

[BritishV8]

Changed the AFR to a custom one as below and it works, reading is within 0.1 now

I'm late to the party, but I wanted to post a THANK YOU to Nige for supplying a solution that worked for me. Now I'm within 0.1 too!

[Nigep]

Changed the AFR to a custom one as below and it works, reading is within 0.1 now

I'm late to the party, but I wanted to post a THANK YOU to Nige for supplying a solution that worked for me. Now I'm within 0.1 too!

Thanks ! I wanted to share as it had been driving me mad !. I`d done all the usualy earthing at different points and it made no difference. I stumbled across the LT401Vette post and thought I`d add that with a small explanation of what I did.

It certainly makes looking at datalogs easier when the AFR tallies to what was being displayed at the tim