Menu
Home
Post Something
Forums
Current Activity
New posts
Search forums
What's new
New posts
Latest activity
News & Features
The Marketplace
Cars for Sale
Engine and Performance
Chassis and Wheels
Exterior and Body
Interior and Cockpit
ICE - In Car Entertainment
Car Shops and Services
Toys and Wares
All Other Stuff
Jobs and Vacancies
Looking For
Members
Log in
Register
What's new
Search
Search
Search titles only
By:
Current Activity
New posts
Search forums
Menu
Log in
Register
Reply to thread
See what others are reading now! Try Forums >
Current Activity
Home
Forums
Main Forums
Interests
Do-It-Yourself Garage
[DIY] Testing an O2 Sensor
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="drexchan" data-source="post: 668126" data-attributes="member: 6936"><p><strong>Let's start with some basic on how Oxygen Sensor works in the EFi system.</strong></p><p></p><p>An http://drexchan.fotopic.net/p16912724.html generates a voltage output within the 0V to 1V range when fully warmed up to the operating teperature, 315°C and above. The voltage generated depends on the <u>amount of oxygen in the exhaust stream</u> and accurate reading can only be achieved when it's warmed up to the operating temperature.</p><p></p><p>The input from the O2 sensor is used by the ECU to keep the air/fuel ratio as stoiciometric (14.7) as possible. That means that for every gram of petrol the engine burns, it will need 14.7 grams of air, or 3.1g of oxygen.</p><p></p><p>This is commonly known as the O2 feedback system and when this system is operating it is said to be in "closed loop". When it is not operating, meaning the computer is not reading and responding to the oxygen sensor, it is said to be in "open loop".</p><p></p><p>All O2 sensors are vented to the atmosphere which contains approximately 21% oxygen. The exhaust of a ideally-tuned petrol-powered engine typically contains 2% oxygen, max.</p><p></p><p>Lean: If the exhaust has > 2% oxygen, it is lean (A/F ratio > 14.7). This produces a low voltage of < 0.3V.</p><p></p><p>Rich: If the exhaust has near 0% oxygen, it is rich (A/F ratio < 14.7). This produces a high voltage of > 0.6V.</p><p></p><p>The voltage signals are sent to the ECU and it reacts by adjusting the air/fuel ratio. The signal output is therefore fluctuating around 0.45V in a sinus pattern. Each cycle take less than 0.3 sec for a healthy, sensitive sensor.</p><p></p><p>In order to read the O2 sensor, most ECU send out a certain voltage to the output terminal of the sensor. This is typically around 0.45V. Since we know that the sensor sends low voltage (< 0.3V) when a lean condition is present and a high voltage (> 0.6V) when a rich condition is present, the computer can count the number of times the sensor crosses the 0.45V mark. Cross-counts are the number of times an O2 sensor crosses 0.45V. A scanner such as PDT2000 can read this.</p><p></p><p><strong>The ECU can only use the sensor's output information under certain conditions.</strong></p><p></p><p><em>A] the sensor must be hot to produce a normal signal (> 315°C).</em></p><p>This is why most sensors today have built-in heaters to counteract the cooling effects of prolonged idling and to achieve closed loop mode sooner during warm-up. Heating the sensor also keeps it cleaner and extends its life considerably. The heater usually gets voltage from a constant "key-on" source like the fuel pump relay or a fuse. For the Proton models (such as Wira with S-VDO ECU) are now using a http://drexchan.fotopic.net/p16912727.html, from NTK, Japan. The four wires are:</p><p></p><p>1. O2 sensor output (black)</p><p>2. O2 sensor ground (gray)</p><p>3. 12V heater feed (white)</p><p>4. 12V heater ground (white).</p><p></p><p>B] The ECU is programmed not to go into closed loop operation until the coolant temperature sensor tells the computer the engine is warmed up. If the system tries to go into closed loop too early in the warm-up period, the leaning effect of the system would cause driveability problems and pollutants.</p><p></p><p>C] The ECU is also programmed to ignore the O2 sensor at near wide open throttle conditions. Maximum power requires maximum enrichment.</p><p></p><p>We can then conclude that O2 sensor feedback is used when the engine is <u>warmed up</u>, at <u>Idle</u>, and at <u>part throttle</u> (cruise) conditions.</p></blockquote><p></p>
[QUOTE="drexchan, post: 668126, member: 6936"] [b]Let's start with some basic on how Oxygen Sensor works in the EFi system.[/b] An http://drexchan.fotopic.net/p16912724.html generates a voltage output within the 0V to 1V range when fully warmed up to the operating teperature, 315°C and above. The voltage generated depends on the [u]amount of oxygen in the exhaust stream[/u] and accurate reading can only be achieved when it's warmed up to the operating temperature. The input from the O2 sensor is used by the ECU to keep the air/fuel ratio as stoiciometric (14.7) as possible. That means that for every gram of petrol the engine burns, it will need 14.7 grams of air, or 3.1g of oxygen. This is commonly known as the O2 feedback system and when this system is operating it is said to be in "closed loop". When it is not operating, meaning the computer is not reading and responding to the oxygen sensor, it is said to be in "open loop". All O2 sensors are vented to the atmosphere which contains approximately 21% oxygen. The exhaust of a ideally-tuned petrol-powered engine typically contains 2% oxygen, max. Lean: If the exhaust has > 2% oxygen, it is lean (A/F ratio > 14.7). This produces a low voltage of < 0.3V. Rich: If the exhaust has near 0% oxygen, it is rich (A/F ratio < 14.7). This produces a high voltage of > 0.6V. The voltage signals are sent to the ECU and it reacts by adjusting the air/fuel ratio. The signal output is therefore fluctuating around 0.45V in a sinus pattern. Each cycle take less than 0.3 sec for a healthy, sensitive sensor. In order to read the O2 sensor, most ECU send out a certain voltage to the output terminal of the sensor. This is typically around 0.45V. Since we know that the sensor sends low voltage (< 0.3V) when a lean condition is present and a high voltage (> 0.6V) when a rich condition is present, the computer can count the number of times the sensor crosses the 0.45V mark. Cross-counts are the number of times an O2 sensor crosses 0.45V. A scanner such as PDT2000 can read this. [b]The ECU can only use the sensor's output information under certain conditions.[/b] [i]A] the sensor must be hot to produce a normal signal (> 315°C).[/i] This is why most sensors today have built-in heaters to counteract the cooling effects of prolonged idling and to achieve closed loop mode sooner during warm-up. Heating the sensor also keeps it cleaner and extends its life considerably. The heater usually gets voltage from a constant "key-on" source like the fuel pump relay or a fuse. For the Proton models (such as Wira with S-VDO ECU) are now using a http://drexchan.fotopic.net/p16912727.html, from NTK, Japan. The four wires are: 1. O2 sensor output (black) 2. O2 sensor ground (gray) 3. 12V heater feed (white) 4. 12V heater ground (white). B] The ECU is programmed not to go into closed loop operation until the coolant temperature sensor tells the computer the engine is warmed up. If the system tries to go into closed loop too early in the warm-up period, the leaning effect of the system would cause driveability problems and pollutants. C] The ECU is also programmed to ignore the O2 sensor at near wide open throttle conditions. Maximum power requires maximum enrichment. We can then conclude that O2 sensor feedback is used when the engine is [u]warmed up[/u], at [u]Idle[/u], and at [u]part throttle[/u] (cruise) conditions. [/QUOTE]
Insert quotes…
Verification
Post reply
The Marketplace Latest
R35 GTR 2020 Original Rim Wheels
Started by
aycy
Chassis and Wheels
Greddy Trust R35 Y Pipe GTR GTR35 Exhaust Used
Started by
aycy
Exterior and Body
Nissan Silvia S15 Door Trim Card Panel Bride
Started by
aycy
Interior and Cockpit
Atlas Force UHP Used Tire Tyre 275 35 20
Started by
aycy
Chassis and Wheels
R35 GTR Ohlins Adjustable Suspension
Started by
aycy
Chassis and Wheels
Nismo LMGT4 40th Anniversary 18x9.5+12 White
Started by
aycy
Chassis and Wheels
Rays G025 18 inch VW Audi S3 A45 CLA45 Golf MK7 MK8 Rim
Started by
aycy
Chassis and Wheels
S13 S14 S15 Used Drift Rim Tire Set
Started by
aycy
Chassis and Wheels
R35 Used Titanium Exhaust
Started by
aycy
Engine and Performance
PWR FL5 / FK8 Street Radiator 42MM
Started by
aycy
Engine and Performance
Posts refresh every 5 minutes
air filter swap question
hi guys,
need assistance.
i'm currently using a Blitz Sus Power Air Filter, and want to change to an Apexi Power Intake Filter.
the question is, if i do so, will i need to change the adapter too?
thanks in...
Ignition Timing Acceleration Adjustment
Refer to the adjustment map.........sifu's
Acceleration Ignition Map - Ignition timing can also be corrected for a rapid change in the throttle opening rate for a smoother transition into wide open throttle...
4G93P fitted with GSR turbo
just wondering are our local 4g93P blocks good enough to bolt on the gsr turbo?
thanks.
Recent Posts
Looking for 2.5-16 cosworth halfcut for 190E
Started by
Tuanku.J
Euro
Thrills and Spills at Zhuhai: Porsche Carrera Cup Asia Rounds 3 & 4 Recap
Started by
The_Mechanic
News and Features
Proton Records High Demand for S70 with 1 Unit Booked every 4 minutes
Started by
The_Mechanic
News and Features
Toyota Malaysia Enters Regional GT Racing with TGR Racing Malaysia
Started by
The_Mechanic
News and Features
Home Win and Double Podium for Akash Nandy at Sepang Season Opener
Started by
The_Mechanic
News and Features
Search
Online now
Enjoying Zerotohundred?
Log-in
for an ad-less experience
Home
Forums
Main Forums
Interests
Do-It-Yourself Garage
[DIY] Testing an O2 Sensor