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Questions tagged [maf]

Anything related to MAF (Mass Air Flow) sensors.

14
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3answers
46k views

What is the difference between a MAP and a MAF sensor

Generally a car uses either MAP or MAF to determine the air flow index the engine is getting and that older cars used to have MAP and newer ones often use MAF and cars like the Mitsubishi EVO uses ...
12
votes
1answer
557 views

How is it advantageous for fuel management to detect negative mass air flow?

Here is the flow-voltage mapping for the Bosch sensor utilized by my E39 M5. I find it curious that readings below 0.9 V correspond to negative flows. Questions Is it possible that air can flow the ...
10
votes
2answers
17k views

Power loss in truck - triage options?

I've asked at least one question about my specific situation earlier, but at this point, I'm looking for information on how to operate in triage mode, my primary goal is to get my truck working well ...
9
votes
3answers
55k views

Mass Air Flow Expected Values

I have a 2002 Audi A4 Quattro 3.0. I have a Vagcom USB cable and I am trying to diagnose the MAF sensor. I had a friend get some readings from an OBD2 scanner, which indicated that both precat O2 ...
8
votes
1answer
343 views

Anyone have experience with a faulty fuel press? Regulator?

I've been dealing with a car that starts and then suddenly dies. I replaced the MAF (Mass Air Flow) sensor with a new one, and now it stays on until I press the gas pedal. The throttle body is clean. ...
8
votes
3answers
3k views

Calculating MPG from MAP sensor (or converting MAP data to MAF data)

My 2002 Honda Accord V6 has a Manifold Absolute Pressure sensor (MAP). I understand that this sensor gives out information in pressure units (psi or equivalent). After doing a bit of research, I ...
7
votes
4answers
183k views

Sputtering while driving & idling

[My car: 2004 Mazda 3] So, my wife came home from running some errands and told me the check-engine light was on and that the car was sputtering and felt like it was going to stall while stopped at ...
6
votes
1answer
655 views

1998 V6 Mustang -20+ LTFT on both banks

I just finished doing a bunch of work on my Mustang (replaced all gaskets down to head gaskets on engine, had the heads milled and a valve job done, replaced all the fuel injectors, new fuel injector, ...
6
votes
1answer
653 views

Should you replace the MAF sensor housing when replacing the MAF sensor itself?

When I search for a MAF (mass air flow) sensor on a parts website, I see some that are sold with the housing and some without. A mechanic gave me a quote that correlates price-wise with the full ...
6
votes
1answer
632 views

Is this a right MAF signal?

I've just bought this MAF sensor for the injection setup I'm going to build, and first I was struggling to figure out how to connect it. It's used for several BMW cars.(E38,E39,Z3) On the connector it ...
5
votes
3answers
600 views

Engine shudders when tachometer falls to idle RPM from around 2K RPM

We're talking about a 2005 Volvo S80 2.5T 5-cyl engine vehicle here. Back in late September was the first time I experienced this engine shudder/stutter behavior when the tachometer dial went from say ...
5
votes
1answer
2k views

Why do modern PCMs prefer MAP over MAF

Why do modern PCMs prefer to use pressure sensors to estimate the air charge going into an engine instead of air flow meters. Eg they typically use a MAP sensor and complex software to estimate air ...
5
votes
1answer
4k views

How to clean the MAF sensor on a 1997 Nissan Altima?

I have a 1997 Nissan Altima sedan. I’ve been told the issues I’m having with my car is from the mass air flow sensor. I was wondering how to clean/repair this sensor and contact points the best? What ...
4
votes
1answer
184 views

Chevy 2007 Trailblazer Sputtering in the Morning. Code P0171 has come up in the past

For a little over a month, the P0171 (System too Lean) code has been coming up. My brother has cleaned the throttle and the MAF (Mass Air Flow) sensor. It then worked fine for a few weeks, then the ...
4
votes
1answer
745 views

Calculating AFR using injector flow rate and mass air flow

Is injector flow rate = Mass fuel flow? If so then AFR = MAF/Injector flow rate. Can someone please confirm this?
4
votes
1answer
2k views

Can I use the same AFR sensor on both banks (bank 1 sensor 1 and bank 2 sensor 1)

Have 1mzfe (skip this paragraph if you don't want backstory) codes p1135/p1130/whatever the ones for the other bank are/ all showed up at the same, perfect time. ie when I was broke. Since then car ...
3
votes
2answers
4k views

1996 Ford E350 (5.8L) Mass Air Flow Sensor - where is it?

I can't find the MAF sensor on my 96 Ford E350. (Been googling for hours :)) In case a picture helps: Like I said, I've been looking for quite a while, and I can't find anything. Thanks!
3
votes
1answer
987 views

BMW 320D 2010 hesitating to accelerate while on highway for few seconds

Recently my 2010 BMW 320D had been playing up. Overall performance of the car has been fine. But this weekend it started to struggle to accelerate on the highway for few seconds and was fine ...
3
votes
1answer
554 views

Cleaned throttle body, MAP sensor suddenly dead

(Solstice) So, I cleaned my throttle body with brake cleaner. I thought it was carb cleaner, but I am apparently illiterate. (Honestly, I'm not sure what the difference between them is.) I was very ...
3
votes
1answer
1k views

How can one calculate volumetric efficiency without a MAF sensor?

I am completely new in the field of OBD2 sensor; I am looking for a method (or a formula) to calculate Volumetric Efficiency of: Diesel Car Petrol Car which do not have a MAF sensor. Can anyone help ...
3
votes
1answer
55 views

1986 Corvette - ECM code 33 & 36

My vintage 1986 Corvette convertible recently developed a stumble that progressed to a no-run condition. It comes and goes sometimes starting but in a few minutes I get a SES (Service Engine Soon) ...
2
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4answers
4k views

Check engine lights came up after Air filter change?

Yesterday I changed air filters in my car (Nissan supper saloon N16 - model year 2000). After installation the check engine light came on when I started the engine and the engine seemed to be running ...
2
votes
1answer
12k views

What exactly is OBD Calculated Load?

OBD Calculated Load is defined as: LOAD_PCT = [current airflow] / [(peak airflow at WOT@STP as a function of rpm) * (BARO/29.92) * SQRT(298/(AAT+273))] But when I am in neutral and I open the ...
2
votes
1answer
33 views

Does the air intake system in a VW CC 2010 go around the engine?

I am trying to visualize what the air intake system in my car looks like. It's a turbocharged 2.0L VW engine. As I understand it, the air intake is on the front right near the radiator and headlight....
2
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0answers
349 views

Nissan MAF Volts to Grams per Second Conversion?

So my 99 Nissan Almera GA16DE 1.6L ( Euro Sentra ) is only OBDI, and only provides a voltage PID for the MAF. Anyone know of a conversion from volts to grams per second?
2
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0answers
74 views

2002 Nissan Sentra XE (1.8) bogs down under heavy acceleration

This is my first time asking for help here so please bear with me. As the title says, my 2002 Sentra XE bogs down when my try to accelerate hard. It's more noticeable from a stop, but seems to do ...
2
votes
1answer
480 views

What does the OBD error code P0100 mean?

What does the OBD error code P0100 mean? I have an engine misfire with the check engine light on in my Nissan N16 Supper Saloon -1300cc - 2000 model year. The engine started to produce less power. An ...
1
vote
1answer
56 views

Is there anyway a shade-tree mechanic can check MAF calibration?

When it comes to testing MAF sensor on my vehicle, the factory service manual just suggests two PASS/FAIL tests: an out-of-circuit resistance reading at a particular ambient temperature validating ...
1
vote
3answers
177 views

'98 Subaru Legacy Outback — does this sound like a broken MAF?

Starts fine, idles for a couple seconds, then stalls itself. No CEL the first time or two. Here's a video of the stall behavior. I suspect the MAF because I was recently mucking around removing the ...
1
vote
1answer
173 views

MAF Sensor Performance Code in cold weather

I have a 2011 Nissan Murano with a check engine light that comes on and off. It started once the weather started turning cold, however the check engine light will disappear shortly after I get my OBD ...
1
vote
1answer
2k views

MAF sensor output signal vs. RPM?

I read that the MAF sensor output voltage increases as RPM increases. The ECU uses this voltage to determine other things, like idle RPM, ignition timing, fuel injectors, etc. Where can I find the ...
1
vote
1answer
379 views

IAT reading higher than ambient temp. Is that normal?

My car's engine comes with a Bosch hot film airflow mass meter. The probe inside the sensor's body features both the actual airflow sensor and what looks like a thermistor. I'm telling you that ...
1
vote
1answer
38 views

What kind of MAF sensor is this?

A Bosch MAF sensor from a 1994-1996 Volvo looks like this: I have read about different types of these old sensors and they all mention a "wire", however I cannot see a wire in this sensor, just a ...
1
vote
2answers
6k views

Where is the MAF Sensor on a Peugeot 207?

I'm getting loss of power when idling and spluttering and the OBD is telling me the engine is running rich. I want to try cleaning or replacing the MAF sensor, but... I'm no mechanic and I'm just not ...
1
vote
0answers
40 views

Does MAF has something to do with rough idle?

I am trying to solve my cars long issue in idles again. Cleaning the ICV did the trick before but it keeps coming back and I don't know what else to check. Here's the link in my previous question. ...
1
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0answers
24 views

2001 Nissan Xterra drivability

2001 Nissan Xterra SE, 3.3L V6, automatic, 2WD, towing package, 150k miles Some history, perhaps useful: I bought this vehicle from a friend a few months ago. Vehicle was in good shape for its ...
1
vote
0answers
51 views

Check engine light won't stay off

I've attempted to get my check engine light fixed a couple times and at each repair facility they've scanned the code and told me it was a bad oxygen sensor. I had the oxygen sensor replaced at both ...
0
votes
3answers
2k views

open-loop vs closed loop

My car sprung a P0101 pending code recently, which shows up as a Mass or Volume Air Flow Sensor "A" Circuit Range/Performance on my BlueDriver OBDII scanner. I started to read this article SUCCESSFUL ...
0
votes
2answers
6k views

Why does RPM jump between 1000 and 2000 at standstill (2002 Mercedes-Benz CLK 200 K)?

My car has a kind of a rough idle and it's like it gives a bit of gas, meter goes between 1000 and 2000 rpm at standstill. Same if I shift up to 1 or 2nd gear. If I then take it for a drive, car jerks ...
0
votes
0answers
23 views

MAP or MAF used in Hyundai Accent?

I want to ask, what sensors does this car have? MAP or MAF or both? If it has both, which sensor is used at each point in time?
0
votes
1answer
44 views

Mass Flow Sensor missing

I've recently purchased a Volvo V70 I 2.4 (106kW, 1998, manual) and wanted to check the mass flow sensor for issues. But it appears that my car has none, even though I've seen them in all pictures and ...
0
votes
0answers
17 views

Possible leaky vacuum hoses?

I have a 2011 Nissan Murano with an intermittent MAF sensor OBD code indicating poor performance. After trying to clean the MAF sensor and eventually replacing the MAF sensor, I am still continuing ...
0
votes
0answers
28 views

What kind of MAF sensor does Volvo 850 have?

I cleaned my MAF sensor in my 1996 Volvo 850 by removing it and swabbing it with alcohol and I am wondering what type it is and whether I cleaned it correctly. I saw no wires. It was kind of a ...
0
votes
1answer
286 views

p0104 MAF sensor

I'm having a P0104 error code, but there's no MAF sensor in my car (Focus mk2). There is a MAP sensor in it, but that should have another error code. Any idea how this is possible ?