I have a new OEM RHD FD harness that I cannot seem to connect to the EGR function sensor. I am fairly certain that I have identified the correct plug on the new harness based on the wiring color codes from the FSM. The sensor connector itself has two longer orange plastic prongs that extend (on the the top of the connector in the photo below) which looks like it should mate to the bottom of the interior part of the blue connector, however the keyways on the sides of the connector prevent this orientation. Does anyone have a picture of their EGR function sensor connector or harness connector to see if mine was assembled upside down?

 

what's the model years of all the things involved here? EGR components depend on model year and emission status (FED or California). Is this a right hand drive Japan spec car?

 

As far as I know none of the JDM cars even had EGR. So it shouldn't be on the harness if it's a RHD Japanese harness.

93's had EGR, and 93 California cars had the EGR switch/sensor to feedback to the ECU when the EGR valve moved.

All '94's had the Cali-type EGR setup.

95 in the US they got rid of EGR all together.

The EGR system in the FD is a joke. The gasket has a TINY pinhole for exhaust to go through. I think Mazda knew it was a joke and had to put it on for emissions purposes. That pinhole will get plugged with carbon in no time at all.

What are you trying to accomplish? The car runs great without EGR, it's a very unnecessary system.

Dale

 

EDIT: I'm an idiot and it's a LHD harness for a US spec car, is what the top post should have said.

It's a 1994. I don't think it's a California model, as both previous owners were in TX. Unfortunately I'm in Denver now and I need it to pass emissions. The previous owner(s) had it go through several rounds of modification at Rotary Performance in Dallas and it ended up with a split air blockoff plate, and (presumably) a Bonez DP + cat (which also looks like a 2.5in diameter rigged to the 3in pipe so probably purchased prior to their actual FD exhaust system), but otherwise the emissions system is intact.

End goal is a reliable emissions compliant "restoration" of sorts. It has a new OEM short block with the previous motor's N3G1s and the existing exhaust. I'd really like to complete the D series 20b I have for it, but I don't think it will workout here.

 

As Dale said, the 1993 Cal version of the EGR valve was used nationwide in 94, so in that sense all 94s were California models. Your harness connector looks like the right one.

 

The part I think is upside down is the inner orange part relative to the outer blue body of the plug. On the harness connector, the keyways for the plug body (red) are on the top while the keyways for the orange pin part (green) are on the bottom. Compare that to the photo of the EGR function sensor plug where both the keyways for the plug body and for the inner orange part are on the same side of the connector, in this case the top of the photograph. The inner orange part is what I'm thinking is upside down.

 

My old harness had the inner orange part removed completely it seems, leaving only the part of the plug body that supports the pins. Looking at pictures of the Sumitomo DL 90 female connectors online seem to imply that the harness connector is assembled correctly, but I can't find an interior shot of the male connector.

 

Could it be that the orange piece in your EGR valve's connector is actually a broken piece of the damaged harness's connector? I think the crank angle sensor uses the same type of connector, and it has 2 metal prongs but no orange plastic center piece.

 

Well I didn't even think about this considering how tightly adhered the black inner part is on the EGR connector. Turns out it's very very cooked. The orange part in the EGR did end up coming out, albeit in pieces, leaving prongs similar to the one you linked. I was originally pretty hesitant to pry on the EGR connector side at all, given how much the harness crumbled. This was the solution, thanks for restoring my sanity.