Check Engine Light Due to Restricted EGR System on Toyota Corolla

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: 181,303 (90,000–297,000)
9 model years affected: 1990, 1991, 1992, 1993, more1994, 1995, 1996, 1997, 2004
40 people reported this problem
Viewing 1 - 11 of 11 comments
Egr.code p0401 corolla 97. Change egr vale egr modulatorclean intake still check engine light come back
Engine Code P0401 showed up on my scanner. Just needed to replace the Vacuum Control Module. Cheap and easy. Love my car!
Cleaned EGR but CEL still on:(
I am having toyato corolla 2004 I am suffering a problem at the time when car is stopped or not working for more than 5 to 6 hours there is problem like when we start the car it starts immediately but after half minute engine stoppes and than
Engine code 71 have cleaned out egr somewhat cleared the light in the car runs fine for a couple days then the check engine light comes back on for the same code still need to check vsv vacuum sensor temperature sensor for egr
egr restricted flow replaced all components
EGR is block
I un hooked the battery and cleaned the egr valve.after driving for an hour the light came back on.I realized a hose was just a little loose and so far no light.
Check engine light turned on. EGR valve completely clogged. Cleaned valve and reset engine light.
Code 71 EGR Temperature
Running just fine, then hopping on the Interstate the Check Engine light came on. I am not aware of any running issues with this car.