Just installed a Magnaflow complete exhaust system with a no name header. My question is with what I believe is the EGR, a pipe that threads into the exhaust manifold or header and runs under the intake system. OEM manifold was female threaded and the pipe has a B-nut male threaded. Replacement header has a male thread hookup requiring a female thread B-nut. Is there an adapter I can get that will connect the header to the pipe? And where can I get one? Have 2 weeks to get this operational, have an autocross on the 23rd I'd like to try out the new (to me) exhaust. If need to know, my car is a 99 NB base with replacement engine out of a 2000. Header and exhaust come off a 99 10AE. Everything else fit like it's supposed to. Just this one connection is stalling the task.
Your header is for a different year. If it fits at the cat flange, that tells me it's for a 2001-05. A 2001-05 EGR pipe should fit.
Or it's an eBay special and you're just lucky it has the right number of exhaust ports 
mapper
HalfDork
10/11/16 7:02 a.m.
On my 99, I plugged the port on the header and cut an aluminum plate for the backside of the intake and the car had no issues until I had pass OBDII emissions. So if you do not have to have an emissions test I say block off both ends.
Thanks everyone. Alabama - no emissions testing but I would rather hook it up rather than block it off. Was installed on a 99 10AE before I installed it on my 99, I would have thought the engines would have the same hook ups. Oh well, looks like I need to find an adapter to hook it up or a EGR pipe that matches.
I've never seen an adapter. Get the right pipe.
I suspect the other 99 already had the matching EGR pipe and you just didn't get it with the header.
1999-00 EGR pipe:
01-05 EGR pipe:
Yep. The top is the one on the car and the bottom is what I need. Ordered one tonight. Hope it comes in before next Sunday.
To close out this thread. Took Keith's advice. Digging around the internet I found that Cobalt makes an EGR pipe to fit headers on a 99-00 Miata. I thought it was a bit much for what it is at $60 but ordered it anyway. Wasn't expecting it till Thursday but came in today. Took less than 5 minutes to install. Fired up the car and learned why the guy I bought it from removed it from his 10AE and went back to stock. It is louder than the stock exhaust with a small Magnaflow muffler I had on it but tolerable for how much I drive the car and what I use the car for. Took it on a test drive and pleasantly surprised at how much the acceleration increased. Can't wait to try it out at the autocross this Sunday.
