'97 NA8 EGR?

apsilon · Postby **apsilon** » Mon Mar 26, 2018 5:34 pm

So, hypothetically.... if someone were to say buy a very nice aftermarket Japanese header for a good price and then when it arrived found it doesn't have the port for EGR and so decided to remove the EGR system for track use, is the ECU going to throw a CEL or any other kind of tantrum?

I know it would on newer cars but not sure about this era. I'm also assuming the EGR port is in the same location as the US cars as that's the only photos/vids I've been able to find in my quick search. I haven't had time to pull the heat shield off and actually check.

I guess I could have an exhaust shop add the necessary bung to connect the EGR, that might be the easiest solution as I don't want to go to a programmable ECU at this time.

hks_kansei · Postby **hks_kansei** » Mon Mar 26, 2018 5:38 pm

CEL won't be an issue since Aussie cars don't have one.

As far as how the car runs, I blocked off the egr on my NB8a a while back and didn't notice any change in how it drove

The wideband I had fitted at the time didn't show any odd afr either (stock ecu, wideband was running totally independent of the ecu back then)

Granted, I only drove it like that for maybe 2 months before I put in the adaptronic.

takai · Postby **takai** » Mon Mar 26, 2018 5:58 pm

hks_kansei wrote:CEL won't be an issue since Aussie cars don't have one.

When did we get CELs? Was it in the NB range?

apsilon · Postby **apsilon** » Mon Mar 26, 2018 7:21 pm

Good info, thanks.

I'll pull the heatshield over the weekend hopefully and have a look at how/where the EGR connects. I'm not really interested in deleting it. I expected this header would just be a no issue bolt on but looks like I'll need to get an exhaust shop involved because I sure can't weld well enough to work on what is an otherwise beautiful piece. Do the JDM cars not have EGR? I was under the impression that JASMA certification would cover pollution gear but I'm guessing it just covers noise?

Got a little time to work it all out as the back half of the exhaust won't arrive for another week anyway.

hks_kansei · Postby **hks_kansei** » Mon Mar 26, 2018 8:31 pm

takai wrote:
hks_kansei wrote:CEL won't be an issue since Aussie cars don't have one.

When did we get CELs? Was it in the NB range?

MAYBE late NB's, but i know the NB8A doesn't have it for sure.

hks_kansei · Postby **hks_kansei** » Mon Mar 26, 2018 8:42 pm

apsilon wrote:Good info, thanks.

I'll pull the heatshield over the weekend hopefully and have a look at how/where the EGR connects. I'm not really interested in deleting it. I expected this header would just be a no issue bolt on but looks like I'll need to get an exhaust shop involved because I sure can't weld well enough to work on what is an otherwise beautiful piece. Do the JDM cars not have EGR? I was under the impression that JASMA certification would cover pollution gear but I'm guessing it just covers noise?

Got a little time to work it all out as the back half of the exhaust won't arrive for another week anyway.

Yeah, Jasma from my understanding is more a volume and quality test than any kind of emissions.

But as well as that, i dont believe the Japanese models had EGR anyway.

As far as deleting it, there are two parts to deal with.

one is at the extractors, on cyl #4's runner (I think NA8 may be on #2?) either way, you'll see an ugly rusty pipe on one of them, you'll need to remove that.
Buy penetrating oil, WD40 works ok, but penetrating lube works better. put it on the day before to really soak in.
There's a 99% chance it will be rusted on TIGHT and due to heat cycling the metal will be weakened.
Frankly, removing the EGR pipe is a farking arse of a job.

the other part of a delete is at the intake manifold, on the NB8A it was simply two 10mm bolts that came out easily, once these are removed you'll find the EGR pipe is loose, you'll also have a thin metal gasket, keep that handy.

use the gasket to trace the shape onto a sheet of flat metal, you'll want 3mm steel min so it seals, cut it out and drill the mount holes (dont drill the centre hole where the pipe connects)
Once you've done that, you'll put the gasket back (or make a new one from gasket paper) and use the steel blanking plate instead of the EGR pipe.
this is needed so the intake manifold doesnt just have a huge leak.

As far as ECU codes, it should be fine since you're leaving the EGR valve in place, as far as the ECU knows it's still opening and closing, so it's working.
What it wont know though is that there's no exhaust passing though it anymore.

regarding the EGR blank plate on the manifold, if you dont have the skill/facilities to make one you can buy them ready made.
I'd offer to make one for you for the cost of postage, but i've just moved house and cant actually walk in my garage yet due to the boxes.

hks_kansei · Postby **hks_kansei** » Mon Mar 26, 2018 8:45 pm

https://www.flyinmiata.com/egr-block-off-plate.html

here's the blank plate.
Looks like the NA8 one is slightly diff to the NB one, but same concept.

Regarding the comment on their page about the CEL, as I said, my 1999 MX acted 100% normal with it removed, no lights etc. (granted, i never bothered to check for codes with the old LED trick)

I suspect the error code from the EGR is a US thing, the california market has some really strange rules that meant a lot of US cars had weird options the rest of the world never had, like NAs with airbags, and dual catalytic converters.

apsilon · Postby **apsilon** » Mon Mar 26, 2018 9:04 pm

Thanks. Food for thought.

I can make a blanking plate no worries though I don't have any suitable sheet stock on hand. Should be able to get an offcut from a local metal supplier but I'll talk to the exhaust place first.

hks_kansei · Postby **hks_kansei** » Mon Mar 26, 2018 9:06 pm

yeah, scrapyard would likely have something for free.

I just used some sheet steel from bunnings that I had a few offcuts of from a previous project.

93_Clubman · Postby **93_Clubman** » Tue Mar 27, 2018 12:01 am

96-97 NA8 did have some differences from 93-95 NA8, but don't believe EGR was one of them in the Aust domestic market. In other words, early ADM NA8 didn't have EGR, so believe late ADM NA8 didn't have EGR either.

apsilon · Postby **apsilon** » Tue Mar 27, 2018 6:46 am

That would be good news. Easter weekend coming up so I'll have time to take a look and hopefully change the oil and filter. I have had a quick look with the heat shield on and couldn't see the pipe I expected for EGR but the shield does block the view rather well so just put it down to that but perhaps it's not there at all which would be nice.

EDIT: may as well ask while I'm at it, do the ADM 96-97 cars have a second O2 sensor after the cat? I've had a look with the car on the ground and couldn't see anything but it's not easy to see the top of the exhaust. The RM-01A comes with a note that it doesn't have a bung for the second O2 sensor on those cars but wondering if that doesn't apply either.

hks_kansei · Postby **hks_kansei** » Tue Mar 27, 2018 9:34 am

I dont believe we ever got the second o2 sensor, maybe the very late NB, but the NB8A only has the one sensor.

If your car is a Japanese import it may have a heat sensor around that area, but that can simply be removed and the bulb for the "heat" lamp on the dash removed as well.
Most of those temp sensors dont work anymore anyway.

But yeah, as far as the Aussie cars go, we only got the one sensor to my knowledge.

Regarding the EGR tube, if you can get a light in there, if the car has EGR, you'll see a steel tube, about the diameter of a 10c coin, running from the back of the intake manifold, behind the head (between the engine and firewall) to the exhaust manifold.
Otherwise yeah, once the heat shield is off it will be pretty obvious where it attaches.