Calling all in B5 S4 BT....

PSmalls::DoggieStyle · 08-26-2005, 01:38 PM

I logged SLPRS4s car last night running XR on 100 octane. He is a basic stage 1, no exhaust or DPs. His car pulled a 5.00x FATS time, which I think is very respectable considering it was in the 70s.

The first thing I noticed when taking a look at the ECUx log was a dead/dying B1S1 02 sensor. Take a look for yourself:

Now here come the questions:

A.) Does the ECU take the average of the 2 values or what?

B.) How much is that affecting power output? What gains would you expect to see after swapping in a good 02 sensor?

FWIW, no codes and car felt nice.

PSmalls::DoggieStyle · 08-26-2005, 01:52 PM

Imolavirus@BuehnEngineering · 08-26-2005, 01:53 PM

PSmalls::DoggieStyle · 08-26-2005, 01:54 PM

I swear I've heard here that it averages, but my memory may be playing tricks on me.

sj6sp · 08-26-2005, 02:00 PM

Take a look at LTFT on that car and see if the side you think has a bad sensor is adding fuel (since it is seeing leaner than actual conditions)

PSmalls::DoggieStyle · 08-26-2005, 02:01 PM

Imolavirus@BuehnEngineering · 08-26-2005, 02:04 PM

BiturboBoy_V2.0_S3-- · 08-26-2005, 02:05 PM

your good FATS time is probably because the S4 runs closed loop at WOT, no?
i was udnerthe impression that O2's from each bank are suppossed to match up with each other fairly well.

PSmalls::DoggieStyle · 08-26-2005, 02:06 PM

Imolavirus@BuehnEngineering · 08-26-2005, 02:08 PM

if the O2 just failed i don't see it causing much of a change in LTFT's if they haven't been cleared lately.

08-26-2005, 01:38 PM	#1
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Calling all in B5 S4 BT.... I logged SLPRS4s car last night running XR on 100 octane. He is a basic stage 1, no exhaust or DPs. His car pulled a 5.00x FATS time, which I think is very respectable considering it was in the 70s. The first thing I noticed when taking a look at the ECUx log was a dead/dying B1S1 02 sensor. Take a look for yourself: Now here come the questions: A.) Does the ECU take the average of the 2 values or what? B.) How much is that affecting power output? What gains would you expect to see after swapping in a good 02 sensor? FWIW, no codes and car felt nice.

08-26-2005, 01:52 PM	#2
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Sure, ygm.

08-26-2005, 01:53 PM	#3
Imolavirus@BuehnEngineering AudiWorld Super User Garage is empty, add now Join Date: Mar 2002 Posts: 17,943	won't the ECU trim each specific bank corresponding to what values it gets from each O2 sensor? __________________ -Jacob ^^^CLICK SIG FOR BUEHN ENGINEERING WEBSITE^^^ <big><big>Website Here!!!</big></big> <big>Items For Sale</big>

08-26-2005, 01:54 PM	#4
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Precisely why I posted. I was hoping for an informative technical discussion here. I swear I've heard here that it averages, but my memory may be playing tricks on me.

08-26-2005, 02:00 PM	#5
sj6sp Member Garage is empty, add now Join Date: Feb 2002 Posts: 2,908	...thus you can have two slightly different LTFT (M) Take a look at LTFT on that car and see if the side you think has a bad sensor is adding fuel (since it is seeing leaner than actual conditions) __________________ <A HREF="http://www.marsavius.net/qclub" target="_blank"> </a>

08-26-2005, 02:01 PM	#6
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Nope, both were -.8% part throttle....another reason why I think they are averaged.

08-26-2005, 02:04 PM	#7
Imolavirus@BuehnEngineering AudiWorld Super User Garage is empty, add now Join Date: Mar 2002 Posts: 17,943	when was the last time the LTFT's were reset? __________________ -Jacob ^^^CLICK SIG FOR BUEHN ENGINEERING WEBSITE^^^ <big><big>Website Here!!!</big></big> <big>Items For Sale</big>

08-26-2005, 02:05 PM	#8
BiturboBoy_V2.0_S3-- Elder Member Garage is empty, add now Join Date: Dec 2000 Posts: 12,498	well your good FATS time is probably because the S4 runs closed loop at WOT, no? i was udnerthe impression that O2's from each bank are suppossed to match up with each other fairly well. __________________ AWESOME post, funny and informative for newbs...its not all right but i suggest you click!

08-26-2005, 02:06 PM	#9
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Long time since he never has codes to clear.

08-26-2005, 02:08 PM	#10
Imolavirus@BuehnEngineering AudiWorld Super User Garage is empty, add now Join Date: Mar 2002 Posts: 17,943	reset them and see what they do if the O2 just failed i don't see it causing much of a change in LTFT's if they haven't been cleared lately. __________________ -Jacob ^^^CLICK SIG FOR BUEHN ENGINEERING WEBSITE^^^ <big><big>Website Here!!!</big></big> <big>Items For Sale</big>

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