Sensors 2 Flashcards
EGR reduces?
NOx
What has no energy and will not combust?
Inert gas
Where is the ERG located?
On or near intake with pipe to the exhaust manifold
Common fault on the EGR?
Stick open or shut
What does a stuck open EFR react?
Causes vacuum leak and engine with surge or stall
How can an EGR be controlled?
Vacuum or electronically
What sensor monitors the EGR?
The MAP sensor
When is EGR open?
Cruise and deceleration
VVT has more or tell EGR?
None
What does the MAF measure?
Amount of air mass entering the engine
Three types of MAF sensors?
Vane, Hot Film, and Hot Wire
Hot wire MAR sensors have what kind of circuit?
Burn off
How do you test the MAF?
Tap test
On a MAF as voltage increases as air _____?
Increases
Common fault with MAF?
Dirty sensor or faults (pirate) air
Dirty sensor will read?
Rich
False air will read?
Lean
How do you clean MAF sensor?
Electronics cleaner
Where is the MAF located?
Between air cleaner and throttle body
What does the EGR do?
Adds exhaust into intake to lower cylinder temp
What does the MAP sensor measure?
Engine vacuum which senses engine load
When is air more dense?
Low altitude and low temperatures
As vacuum increases voltage ____?
Decreases
At idle what is vacuum?
High
What is vacuum at WOT?
Zero
Where is the MAP locates and how many wires?
Near intake manifold
3 wire
What does the MAP do and why?
Sense load, altitude EGR operation to adjust fuel and spark
What is built into a BMAP?
Barometric pressure sensor
What special MAP should do you need on a boosted engine?
One thy measures positive pressures also
Common fault in MAP?
Vacuum line breaks going to sensor
How do you test MAP?
Hook up vacuum gauge and apply vacuum and voltage should drop
What are hydrocarbons?
Raw fuel
What causes carbon monoxide?
Rich mixture will cause death
What condition produces NOx?
Running lean
Above 2500 F
How is smog formed?
Sunlight+HC+NOx
What are the 3 main elements of the CAT
Platinum, palladium, and Rhodium
What is the 4th element of the CAT?
Cerium and it stores 02
What designs Do most CATs have?
Honey comb
What are the first and second beds in the CAT?
1st is reduction bed
2nd is oxidation bed
What does the reduction bed do?
Strips HC particles
What does the oxidation bed do?
Odds oxygen to particles
What three emissions do engines produce?
HC
CO
NOx
Converter turns the emissions into what four things?
CO2
O2
H2O
Nitrogen
