hey guys i have a 98 hx. just did a d16y8 swap. ecu, wire harness and head. problem im having is im running very rich, i have carbon all over my bumper and blow black smoke like crazy. i currently have no second o2 sensor (no plug in) mods i have are, skunk2 mani, header, crower stage2 cam intake HELP!

 

you have no second O2, that is your problem

 

are you sure? ive been told that all the second one does is read tyhe cat and nothing else..i thought it was the o2 as well but been so confused of its purpose..car runs great cold when warms it runs liek crap and idle everywhere

 

well is the second one a heated o2 sensor?

 

far as i know its suppose to be

 

i have a 97 hx that i swapped a d15bvtec in and i am running obd2 and i am having the same problem as you are. i have come to the conclusion that on our hx's we have a 5 wire wideband o2 sensor and that the ecu will not read from it so you need to rewire it to read from a 4 wire sensor... i am working on fixing mine at the moment and i will let you know how it goes.

 

Also an hx owner and having the same problem, let me know how that goes calebchesh

 

did you check the condition of the motor before swapping, i know a lot of people that usually skip that step