I started the car (a 2012 2.0 litre) a couple of weeks ago & the engine management warning light came on immediately although it seemed to drive O.K. The independent garage I use found that the fault was with the EGR valve, re-set everything & it’s been fine since. They did say though that they’d recently had a 2011 MX-5 in with the same issue, the light had come on again on 2 further occasions on that one - after which the EGR valve was replaced.
I’m a little concerned in case this occurs again with my car e.g. if I’m a long way from home & wondering whether this fault, if it happens again, may result in a breakdown? Although I do have breakdown / recovery cover of course. The car’s only done just over 23,000 miles & the vast majority of this has been motorway & A-road travel, it hasn’t really been used for short trips & while it isn’t used much during the winter & sits in my dry garage plugged into a CTEK battery charger I do make a point of starting up & running it round for 5 miles or so about once a week when the roads are dry.
I’m also concerned because the EGR valve failed on the day that I took delivery of this car - with less than 20 miles on the clock - in fact the engine management warning light came on before I’d even got my brand new car home from the dealer! They turned the light out but it came on again an hour later following which the valve was replaced under warranty.
I’m aiming to keep the car for some time yet, but I know that the EGR valve isn’t cheap - or easy - to replace.
Maybe I’ve just been unlucky - wondering whether anyone else has experienced what seems to be a recurring EGR valve problem on a Mk3 / 3.5 / 3.75?
I had the EGR valve removed and a blanking plate installed on my 200SX, can’t the same be done on the MX5?
I see you are in Sheffield, I’d be giving Paul Roddison (Roddisons Motorsport) a call and asking for his advice if I were you.
Hope this helps.