I have a 96 Miata that has 3 sensors that are not getting into the 'ready' state, they are the EGR, CAT, and O2 sensors (my car is not throwing a CEL). I have cleaned the EGR valve, checked the rubber hoses for any cloggage, changed my o2 sensors and I installed a new Magnaflow cat on my car about 2 years ago.
One thing I would like to mention is that the previous owner removed the egr tube and I have been running my car without a tube for about 6-7 years now, but I have recently put but a EGR tube onto the intake manifold. Hopefully driving for 2 years without a egr tube did not destroy my CAT.
I have been trying to do some recommended drive cycles to get these sensors online but have not been successful. I will try a few more but I am thinking that something may actually be going haywire, maybe the EGR valve is faulty or I may need to replace the EGR booster sensor. Any help to solve this problem would be great! My registration just expired last month. Thanks!
I also recently brought my car to a Miata specialist and they could not get my sensors going either, he said that it is most likely the EGR valve that needs replacing. I should be getting a used EGR valve shortly... hopefully that solves my problem!
-Will