alright so iv got a 97 that i just bought and i just noticed it was idling at 2k. iv searched but none of its really making sense or not what I'm looking for. its got a shitty race land header on it and I'm thinking its stuck in closed loop because the o2 is down by the collector. I'm probably wrong but thats the only reason i can think of. when it idles its blowing smoke out of the exhaust and it smells like gas with makes since to me that its in closed loop cuz its running rich. anyways i don't really know how to address this and where i should start

 

The idle screw is backed all of the way out already and still idles at 2k. It smokes it's *** off when I start it and it smells like gas so I know puts running rich. Any help?

 

what color is the car?

 

Thanks for the help

 

IIRC 1997 was an OBD2 car. Is it throwing a code?

It's a valid question. The information you've given is pretty much worthless. Get us more details an we can help you troubleshoot the car, depending on what color it is of course.

 

It would be in open loop if the O2 sensor wasn't working.

 

Well basically when I start the car it oldest 2k and stays there even at operating temps. Iv adjusted the idle set screw and no change. Iv read that the butterfly could have some build up in it and not allowing it to fully close but iv pressed On it and it won't go down. I'm kinda new to miatas and fuel injection (iv always been a carburetEd small block Chevy kinda Guy) so I don't know too much about this open ans closed loop. I know these poop raceland headers have the o2 sensor way down at the collector ans I feel like the o2 isn't getting hot enough. Iv also noticed its burning way more gas lately too. It's a blue/green sto btw haha

 

Oh and I havnt had it hooked up to a diagnostics yet so I don't know what kind of code it would come up with. Also the check engine light is on if that means anytjing

 

Finally, some information we can use!

Check engine light on is bad. You can pull the codes yourself. Try this.

Miata Computer Diagnostic Fault Codes

Edit: Nevermind, you have a blue/green car with OBDII. Take it to autozone and they'll read the codes for free.

 

well i borrowed a OBDII code reader from my brother in law and it threw 4 codes. one was o2 bank 1. when i switched it to live data the 02 seems to be working alright so idk why it would throw a code for it. another code was exhaust pressure sensor. idk what thats all about. the other two were EGR but thats been deleted and the last one was a vehicle speed sensor… i also found in the live data that the car is actually idling at like 850 not 2k like my tach says… i wonder if the step motor is back in the instrument cluster or something like that