Mercedes-Benz Forum banner

1 - 6 of 6 Posts

·
Registered
98 SLK230k/02 SLK32
Joined
·
742 Posts
Discussion Starter #1
OT (somewhat): Can I get, or calculate, the A/F ratio using the OBD-2 PC software ? If so, how ?
 

·
Registered
Joined
·
217 Posts
RE: OT (somewhat): Can I get, or calculate, the A/F ratio using the OBD-2 PC software ? If so, how ?

I have the exact same problem and read and made countless searches about it.

If your OBD2 scanner logs like mine, I think the only way is to log the data from the O2 sensor (S1), then on the computer get the average of your data, this will show you if you're under or over .450mV

if you're at .450mV you're at 14.7, under you're rich, over you'Re lean if I remember correctly.

But to calculate the ratio itself it seems to be a PITA.

I know you can also check the long term fuel trim. I compared mine with a friend and his stock car had a way lower fuel trim than mine. Probably my car stored in the "long term" cells values to give more fuel because I have a pulley and need more gaz.

Etienne
 

·
Registered
Joined
·
30 Posts
RE: OT (somewhat): Can I get, or calculate, the A/F ratio using the OBD-2 PC software ? If so, how ?

Unless you get Genesis or snapon scan tools, the cheaper readers don't really diagnose the data. They are mostly only code readers.
 

·
Registered
SLK32, ML430
Joined
·
6,349 Posts
RE: OT (somewhat): Can I get, or calculate, the A/F ratio using the OBD-2 PC software ? If so, how ?

The OBD-2 software you get from OBD2.com can provide lots of good info. Unfortunatly I can not get it to talk to my '03 SLK32. It has no problem communicating with the ML.

It has been a long time since I hooked it up so I can't really answer your question about the A/F ratio. I believe it can be logged, but am not 100%.
 

·
Registered
Joined
·
217 Posts
RE: OT (somewhat): Can I get, or calculate, the A/F ratio using the OBD-2 PC software ? If so, how ?

if you can log, then log all your data from your S1 O2 sensor and then use your computer to compute the average value

Etienne
 
1 - 6 of 6 Posts
Top