MAF replacement input/suggestions

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Oct 22, 2010 | 01:20 PM

#11

Msnickbroderick

Actual WIZARD

Joined: Jan 2010

Posts: 1,047

From: Dallas, Texas

Vented DV = Bov

Oct 22, 2010 | 02:04 PM

#12

Mike-2ptzero

4th Gear

Joined: Apr 2008

Posts: 3,274

From: Phoenix, Arizona area

Quote:

Originally Posted by Keegan0103

Absolutely. Any a4 with a MAP sensor will run mafless, because the ECU will fall back to using the map. I ran this all summer with a cone filter. Upside is you can vent the DV, and not have misfires (yeah it was ricey, but with an open downpipe, it was damn amusing, everyone thought I had the baddest sleeper)

That info is oh so wrong in every way. lol

It has nothing to do with the car having a MAP sensor, it has to do with the fact that the car has a wide band 02 sensor. This is why the 01+ cars can go mafless but yet the 00 can not even though it has a MAP sensor.

The wide band cars use the 02 sensor to adjust the fueling 100% of the time, while the narrow 02 sensor cars (pre 01) only use the 02 sensor to adjust fuel during idle/PT not during WOT.

The MAP sensor is not used for fueling, it is just a safety sensor that tells the ECU if there is an over/under boost issue. ECU doesn't even use that reading to adjust the boost level.

Pre 01 A4 1.8t = Fuel Map and MAF for WOT fueling

01+ A4 1.8t = Fuel Map, MAF and 02 sensor for WOT fueling

The MAF really seems to help at idle vs going MAFless on the 01+, this is because the air flow is so low and tends to jump up/down during idle. The ECU uses the MAF readings to set how much timing it runs since it is using the reading for load. MAFless the ecu just runs straight off the timing map.

Class dismissed

Last edited by Mike-2ptzero; Oct 22, 2010 at 02:11 PM.

Oct 22, 2010 | 02:28 PM

#13

joenelson7687

2nd Gear

Joined: Feb 2010

Posts: 1,407

From: Baltimore, MD

Quote:

Originally Posted by Mike-2ptzero

Class dismissed

I LOL'd...

Oct 22, 2010 | 06:22 PM

#14

BaseDrifter

Site Moderator/B5 Tech Guru

Joined: Feb 2010

Posts: 1,745

From: Bay Area, CA

Ha.

Thanks for the info Mike.

Last edited by BaseDrifter; Oct 22, 2010 at 07:28 PM.

Oct 23, 2010 | 04:14 AM

#15

Msnickbroderick

Actual WIZARD

Joined: Jan 2010

Posts: 1,047

From: Dallas, Texas

I learn more off here than I did in high school.

Thanks for clearing that up for me

Edit:
Does this mean 01 guys could get a wideband gauge and tap it into the current 02 sensor?

Last edited by Msnickbroderick; Oct 23, 2010 at 04:33 AM.