Quiz # 4
NOX
Name ______
1. An overly lean A/F mixture will cause a vehicle to fail an enhanced smog test for:
a. NOx & HC
b. CO
c. HC & C02
d. CO & NOx
2. An EFI vehicle will fail NOx on an enhanced smog test because of:
a. ECT sensor voltage biased high – cold engine
b. Thermostat removed – running too cold
c. MAP sensor voltage biased high – low vacuum
d. MAP sensor voltage biased low – high vacuum
3. An EFI vehicle will fail NOx on an enhanced smog test because of:
a. MAP sensor voltage biased high
b. Thermostat stuck open
c. High fuel pressure
d. Carbon build up in combustion chambers
4. An EFI vehicle will fail NOx on an enhanced smog test because of:
a. Misfire
b. High fuel pressure
c. Open electrical windings in a fuel injector
d. All the above
5. A vehicle that pings on the dyno during an enhanced smog test could:
a. Cause engine damage
b. Fail for NOx
c. Overheat
d. All the above
6. An EFI vehicle fails the NOx portion of an enhanced smog test, you will:
a. Check for high fuel pressure
b. R&R the 02 sensor
c. Check the initial and total timing
d. Scope check for misfire
7. Technician A says if the TAC door is stuck in the normal (ambient air) operating mode it will cause high NOx. Technician B says high fuel pressure will cause high NOx. Who is correct?
a. A
b. B
c. Both A & B
d. Not A or B
8. The three way cat is responsible for the reduction of all the NOx produced by the engine
a. True
b. False
9. An EFI multiport fuel injection vehicle with a MAF sensor will fail for high NOx on an enhanced smog test because of:
a. Saturated evap canister
b. Ignition timing retarded more than 5 degrees from specifications
c. Leaking fuel injector
d. Restricted air intake system
10. An EFI vehicle will fail NOx on an enhanced smog test because of:
a. Low fuel pressure
b. Overheating engine
c. Restricted Radiator
d. All the above