Emission Control Systems Fill in the Blank Questions

Oxides of nitrogen (NO_____) are formed when combustion temperatures reach more than _____ °F.

2500

A(n) _____ emission system stores vapors from the fuel tank in a charcoal canister until certain engine operating conditions are present.

EVAP

The components necessary to form photochemical smog are _____ and _____ exposed to _____ in stagnant air.

NOx, HC, sunlight

The knock sensor module changes the _____ voltage signal to a(n) _____ voltage signal and sends this signal to the PCM.

analog, digital

Evaporative emissions from fuel tanks and evaporative systems are a source of _____ emissions.

hydrocarbon (HC)

Positive crankcase ventilation systems that route crankcase vapors back to the engine's _____ were developed and incorporated into 1961 cars and light trucks sold in California.

intake

emission control systems clean up the exhaust gases after the fuel has been burned.

post combustion

CO emissions are a good indicator of a(n) _____ air-fuel ratio.

rich

HC emissions are caused largely by _____ fuel.

unburned

The EGR valve has been replaced by manipulating the intake valve opening by use of _____.

variable valve timing (VVT)