Having trouble getting my EGR, CAT, and O2 sensors in the 'ready' state.

[Willywongka]

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

[BoBo]

Do you know the code #. I have a 96 and also from the eastbay, so if you need some help or want to match-up your vacuum lines with mine let me know. Just to let you know drive cycles take about 100 miles to set if you cleared the codes with the scanner.

The egr doesn't really go bad. Did you check all of the evap-lines if you have any charcoal pellet clogs? You gotta tells us what codes your throwing, so everyone can get an idea of the problem.

[Willywongka]

Yeah maybe we can meet up sometime to make sure my vacuum lines are definitely connected to the right places. Just to let you know my car is NOT throwing any codes, its just saying that those three monitors are not ready.

[wannafbody]

Sometimes it takes a hundred miles or more for the sensors to reset.

[BoBo]

Yeah maybe we can meet up sometime to make sure my vacuum lines are definitely connected to the right places. Just to let you know my car is NOT throwing any codes, its just saying that those three monitors are not ready.

Is that what it said in the obd scanner?...make sure you drive it on stop and go areas like residential, and freeway miles. You need a certain number of city and freeway miles, and low speed/high speed variation.

[Hyper]

a low voltage maybe?? do you drive the car on a daily basis?? or the issue started after the car sat in a place for a long time?

[Willywongka]

Sometimes it takes a hundred miles or more for the sensors to reset.
Hmmmm, I guess I'll drive a little more. But I swear nothing is ever gonna change =(.


Is that what it said in the obd scanner?...make sure you drive it on stop and go areas like residential, and freeway miles. You need a certain number of city and freeway miles, and low speed/high speed variation.
Yeah, the OBD2 scanner is saying that the EGR, CAT, and 02 sensors are not ready. I've been doing a bunch of varied driving as well as the 'drive cycles' people are recommending people with this problem to do. They say that you may have to do the drive cycles multiple times before all the sensors will go online. It's quite a fucking pain in the ass!


a low voltage maybe?? do you drive the car on a daily basis?? or the issue started after the car sat in a place for a long time?
Well, I doubt it would be that since I drive my car at least 1-4 times a week. The funny thing is, my car passed smog the previous times I've gone over the passed 7 years of ownership and I was not even running a EGR tube and running an after market header. The only thing different now is I'm now running a Carb legal Monster flow CAI, but I doubt that would cause any problems, though I have considered throwing back on my OEM intake box.

The thing is I don't know if these sensors have EVER been in the ready state anyways.

Here's an update though:

So I got spare EGR today, cleaned it, and installed it on my car and double checked the vacuum lines. Drove it around for a bit with no change in the sensors. I'll use my volt meter to check the other EGR mechanisms like the EGR purge solenoid as well as the EGR booster. I've considered replacing those as well... I'm seriously running out of ideas.

[BoBo]

Before you jump into replacing parts make sure your not missing a part or a misplaced evap hose. Use the car battery to check your purge solenoid, bypass valve and vent valve. Make sure those parts aren't clogged up with charcoal pellets. I have dealt with drive cycles before, usually it sets by 60-100 miles. Either it sets with a fault code or it sets for good.

Make sure your gas is 30-70% full, so theres a higher chance the drive cycle will clear. The evap system needs a specific fuel level. Here is some info about drive cycles: http://repairpal.com/how-to-perform-a-basic-drive-cycle

If you are still having issues we can setup a time to meet up, maybe you left something undone or something might be broken.