The EGR System tends to get restricted or blocked with carbon after 100,000- 125,000 miles which will cause an emissions test failure for NOX. If the EGR system is equipped with an EGR temperature sensor it will trigger a Check Engine Light for improper EGR flow. The repair is to clean out the EGR passages and the EGR Temperature sensor. Our technicians tell this repair is pretty straight forward and takes about 1-1.5 hours. It is also wise to verify the EGR system components i.e. the Transducer, EGR Valve and VSV Solenoid at this time.Google+
Car Problem Reports
Toyota 4Runner Failed Emissions Test Due to Blocked EGR System
Toyota 4Runner Problem
Average Mileage: 183,714 mi (100,000 mi - 260,000 mi)
Visitor, 1991 Toyota 4Runner, 100,000 mi
nox failure, they told me both nox need replacing.. Cost? can I fix? Thanx
Visitor, 1990 Toyota 4Runner, 215,000 mi
cleaned out egr after failing emissios. hope it works
Visitor, 1995 Toyota 4Runner, 228,000 mi
lack of power and check engine code 71 egr clogged.
Visitor, 1994 Toyota 4Runner, 135,000 mi
Code 71. Still has not been repaired.
Visitor, 1992 Toyota 4Runner, 150,000 mi
check engine light on...mechanic says i need a new EGR vacuum solenoid or modulator. light came on after running redline fuel system cleaner