Miata MX-5

Check Engine Light Due to Restricted EGR System on Mazda Miata MX-5

Problem Description and Possible Solution

The passages for the Exhaust Gas Recirculation (EGR) system can become restricted or clogged causing the Check Engine Light to illuminate. The EGR valve will need to be inspected and the passages cleaned.

Problem Data
RepairPal Verified
Average mileage: 74,538 (21,206–110,000)
5 model years affected: 1999, 2000, 2003, 2009, more2010
14 people reported this problem
Viewing 1 - 9 of 9 comments
Engine light comes on when checked I get code 420 which has something to do with the o2 sensor and the catalac converter, both have been changed and the light still comes on.
EGR valve failed & clogged. EGR replaced but problem quickly resurfaced. Turned out that the passageway in the valve cover was clogged, too, and had to be reamed out. That fixed the problem entirely. Runs great now.
check engine light repeatedly comes on and occasionally clears itself. code indicates it is caused by clogged EGR valve ports. some sites state this was due to port holes being to small. it further indicates a recall was initiated, but I cannot confirm this on this site.
Have the same problem where the Check Engine light is on. Based upon the computer check, I have replaced the ECV, new plugs, new wires, tune up, new belts, new tires, and the Mazda dealer can't figure out what is going on.
Bought it used with only 15,250 miles in 2016. Have check engine light one for EGR. About to have it checked soon. I still use it like that for now. Weekend use mostly.
EGR is causing the check engine light to come on. This looks like a recall to me I see that I am not the only one with this problem
The check engine light came on and the code read for the EGR system. I replaced egr valve and the light didn't turn off. I had to clean out the throttle body in order to get the light to turn off.