Ok.. I have been looking for weeks for an answer to this question but no avail so here goes again... from the top... I have an 89 dx hatch with a d16a6 swap and the 5 speed dx tranny. As soon as the swap was done I get code one on the ecu combined with the ever so fun check engine light. I got a hold of an ef fsm (factory service manual) and it told me to try o2 sensor, fuel pressure regulator, wiring from o2 sensor to ecu and finally ecu. I have done ALL OF IT!!! Unfortunately I still have this same code one. 1 code... 1 confused mechanic and 1 annoyed driver... should I just drop it or start looking into something else for my problem solver. The idle is really good and the accelerations is just fine. So I dunno man.. I want to continue my build and this is one seriously annoying bump in the road.

 

after u checked everything did u reset the ecu?

 

I am going to sound really dumb right now but how do you reset the ecu? If you mean remove the positive lead on the battery then yes, I did.

 

just take out your cel bulb lol!

 

Who did your DPFI to MPFI conversion? Or did you just keep it DPFI?

Are you positive your O2 sensor is in the right pin on the ECU?

 

check the ground that mounts on the t-stat housing and the one on the tranny. sometimes they are forgotten and cause weird problems

 

remove the hazard fuse under the hood for 10 sseconds to reset the ecu

 

is that possible? i always thought it was the ecu fuse in the engine bay that did that

 

thats what alldata says and it worked for me when i had to reset it

 

I would try another ECU to see if that could be the problem.
My car had a bad ECU that is throwing codes.

 

the ECU and hazard lights are the same fuse - number 34

 

I had the swap done by a shop in Santa maria, ca cuz I didn't have the time or experience to do it myself. I will try the fuse thing and let you guys know.