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View Full Version : Air To Fuel Ratios 13' Abarth



roy23
03-30-2014, 03:54 AM
I want to know whats the normal air to fuel ratios of a stock abarth i know turbocharged engine have diff AFR's to prevent knocking etc....
I have intake,Manual boost Controller,catless Downpipe,(stock exhaust), RRM ecu setting 9 on 93oct(not ultimate ecu)
When i went catless it threw codes, searched and found a solution for the P0139 and other codes several ppl are dealing with..... When i went catless my gas milege would just drop drop and drop like if i was floor it always, no codes for running rich.... Read about Spacers and other mods to fix all the CEL's, Krayz kind of found a solution for himself Vibrant Spacer Smallest Insert Along With A Hollow Spacer, so i gave it a try didnt help but took longer for da CEL, so i went with the medium insert and a spark plug defouler solved all my CEL's im on my 5th or 6th tank and nothing has come up.... But yesterday it threw a code for stuck/biased rich bank1 sensor2.....checked my AFR's at idle it said 13.7-1 and 14.4-1 was ranging there and at highway 14.6-1 and 14.0-1..... So my concern is, is this normal?
Sorry for the long paragraph just want to be clear on my problem......

SMF'er
03-30-2014, 07:42 AM
the ECU with the use of short and long term fuel trim is always trying to get to 14.7:1 at the pre-cat O2 sensor.

roy23
03-30-2014, 07:59 AM
the ECU with the use of short and long term fuel trim is always trying to get to 14.7:1 at the pre-cat O2 sensor.

Yeah but am I Ok or am I running Way To Lean, When I Floor It All Da Way To Redline It Reads 10.5-1 :/

musicsurf
03-30-2014, 08:02 AM
the ECU with the use of short and long term fuel trim is always trying to get to 14.7:1 at the pre-cat O2 sensor.

This. From what I've seen in logs of various cars, this car tends to stay just very slightly rich of stoich (1 lambda) at idle, and runs right at it during cruise (varying some due to slight pedal modulation, load increases, etc.). Out of curiosity, which sensor did you put the spacer on? It should be on the first sensor, before where the cat used to be.

musicsurf
03-30-2014, 08:05 AM
Yeah but am I Ok or am I running Way To Lean, When I Floor It All Da Way To Redline It Reads 10.5-1 :/

That is the rich side of stoich (~14.68). Lean would be over that number. One thing that you have to take into account is that gas with ethanol will lower the afr the engine considers stoich. E10 makes that point ~14.2:1. Lambda will always be 1.0 at stoich and with the variance in gas blends, is the easiest to see an accurate read from.

roy23
03-30-2014, 08:15 AM
That is the rich side of stoich (~14.68). Lean would be over that number. One thing that you have to take into account is that gas with ethanol will lower the afr the engine considers stoich. E10 makes that point ~14.2:1. Lambda will always be 1.0 at stoich and with the variance in gas, is the easiest to see an accurate read from.

I have it on the second sensor thats the sensor thats throws the codes sensor 2 not 1