MTX-L WB install on a '99

[MoonieGT]

For the wideband to work with OEM ECU (I have a megasquirt that's going in the car as well, but I'd like the WB to work with the OEM ECU so that at inspection time I don't have to put NB back in), is the only wire that needs to be connected the NB simulator wire (e.g., the brown wire from MTX-L)? In other words, can I just cut open the stock NB harness and hook up the brown wire to the correct sensor wire and leave the other three wires alone or will this throw a code? FYI, the WB is grounded and powered via other wires.

[SirHustlerEsq]

It will throw a code becuase of the open heater circuit. You want to use a big-dog resistor on the purple/yellow and I believe the blue/white wires under there and propably use a little safety-wire to tie the resistor to the exhaust because it will get fire-hot and burn the car to the ground if you don't. Then you can run the LC-1 all the time and only swap computers and the air meter when inspecting.

[MoonieGT]

I left the GM IAT sensor installed for the last week and no codes so far :). It's just zip tied to something in the engine bay :)

[SirHustlerEsq]

Is it wired? If it is, it's not working and you should take it out becuase I don't know if that operates in a range safe for your computer.

[MoonieGT]

Ok, ya it's wired up... I figured it would throw a code if it was unhappy...

[Rob®]

Just FYI: Just because you're not throwing any codes doesn't mean you will pass a legit OBD2 inspection. You have to have ready codes present (i.e. the systems say they are working). How many, and what, ready codes probably vary from state to state.

[SirHustlerEsq]

Just FYI: Just because you're not throwing any codes doesn't mean you will pass a legit OBD2 inspection. You have to have ready codes present (i.e. the systems say they are working). How many, and what, ready codes probably vary from state to state.

It won't throw a code with the resistor and will report readiness, on a 99 car. I've seen it!!!

[Rob®]

I wasn't replying to you, mr brg. I know resistor tricks work personally as well (not Miata-specific).