5 Speed Swap ECU Smog Question

[unlegendary]

Alright I live in California

My car is a 240sx 1998 that was previously automatic swapped to manual, haha it went pretty good except i'm still running on my automatic ecu

i have access to a 97 ecu but will it pass smog? due to different years and stuff? will it get rid of that CEL?

also since were on the topic of five speed swaps, someone gave me a speed sensor with two black confusing wires. i'm pretty scared to try to put it on the wrong way because i'm not sure if it will fry my stuff.

thanks for reading

- mike

[240esux]

i highly doubt your ecu would make your car not pass smog. but with an auto ecu there is no governor.

[racepar1]

With the auto ecu the only thing that will keep you from passing is the CEL. The '97 ECU will work fine to turn off the CEL and it is OBD2 so I see no reason why it wouldn't pass like that. I have never seen or heard of a smog tech pulling out the ECU to verify that is the exact perfect one for the car. Now if you got reffed, and they were actually open, then maybe but I HIGHLY doubt they would even fail you for that.

[unlegendary]

thanks, that answers my ecu question.

NOW, for the speed sensor problem.. would it fry my stuff? make my speedo read double if i wire it wrong but no frying? lol, i hate wiring.

[racepar1]

They cut the speedo wires??? How stupid! If you hook the wires up backwards the speedo simply won't work, it won't hurt anything else. I would just twist the wires together, drive the car and make sure the speedo works, then either solder or butt-connect them once you are sure they are on correctly.

[projectRDM]

I love fail threads.

A manual ECU isn't the only thing you'll need to pass the CEL test. If the original owner didn't wire in the neutral and 5th gear switches you'll still fail since they're part of the OBD-II system and needed to not trip the light. It's rare that people do that since both switches aren't needed for anything else. Check the codes first, if you have either you'll have to hardwire them straight to the ECU. Right now you have a CEL because the auto ECU is looking for inputs that no longer exist, the manual will do the same. You may also have a CPS code since people never hook those back up, break them, or use an S13 transmission with no provision for it.

For the VSS, it's a signal generator. If wired backwards it just won't work, there's no voltage applied to it.

[unlegendary]

after i put in the ecu and wire in the 5th gear and neutral sensor i'll see if i have a CEL. if i do, i'll check the codes. thanks for your input. i'm pretty sure i grouped those wires with electric tape haha. yeah i put off the wiring for so long.