Bought a 2000 civic ex and the auto tranny was swapped for a manual (S40), it runs fine but I am get several OBD codes preventing me from passing smog test here In so. California. The car still has the auto ECU in it. Codes P1706 (neutral safety switch) P1768(linear solenoid) P1753 (lock up solenoid). There is no clutch pedal safety switch, they just combined the two large blk wires to the auto shift plug together making the car think it's in park. What do I need to do to rid my self of these codes and pass smog test, should I replace the ECU with a manual ECU and if I do, should I also replace the engine and dash wire harnesses or is there an easier way. can the automatic ecu be changed to a manual ecu.

 

Yes replace auto ECU with a manual one. Also the auto EX has a 3 wire IACV and manual is 2 wire, so you will need to get a 2 wire valve and intake and rewire for that. Other than that I don't think anything else needs to be rewired.

You could put a manual DX ECU in, that works with the 3 wire IACV but your VTEC will not work though it would not throw any codes thus be street legal.

 

Thx for the info it really help