so im temporarily using my p30 ecu from del sol OBD1

its chipped and was used wit neptune and crome on my other car for few years.

ecu is 100% good i had it in my del sol and had no codes with chip or without.

i put a b16 in the integra fro now and all the sensors are connected everything is adjusted etc. engine runs good and idles good

in diagnostic mode its a solid cel and regular running is solid cel. ecu reset twice same thing.


engine harness looks good
thermostat ground is there
obd2b>obd1 ecu jumper harness looks ok too i didnt see anything wrong

just looking for more ideas what to check i gotta take it to emissions on monday
CEL needs to be off(the right way not bulb tricks)

 

Did you remove J1 and try it stock?

 

Its on stock map now since its a b16a2
All sensors are connected

 

well...something similar to this happened to me a few months ago. turns out the thermostat ground wire was bad INSIDE the loom not at the connection where it bolts on. try running a wire from the harness where it goes into the jumper harness to a metal ground (i just wound up bolting it to the dashboard bracket)

its a longshot, but it was my issue when i got a solid cel with known good ecu's

 

O2 heater?

 

wouldnt thermostat wire affect the main relay. because thats where it gets the ground from as well.

it wont work properly at all if thermostat ground is bad.


but everything works good just solid cel.

im just gonna hook up the neptune ecu with rtp to check the sensor output

 

found the problem
it was O2 heater element throwing the code


and then i enabled knock sensor and it was throwing a code for that for some reason.

its a good working knock sensor also and stock engine with P30 ecu with working knock board.
why would that happen?

 

I know the thermostat housing ground will give you a solid CEL. But it seems you found the issue.

The knock sensor has always given me issues on chipped ECUs. I usually disable it. But most of the time I'm using a board without the knock board so it only makes sense to disable it.

 

oh and the knock sensor i had a tard moment

i plugged in a p28 ecu with neptune and enabled the knock sensor lol

failed emissions pretty badly today


can it be bad O2 sensor?

is a solid cel and O2 sensor heater cel a sign of bad sensor or an ecu/wiring issue

 

ok so i tried different way today

got a p2t ecu from civic si
got a different used sensor that measured good


plug it in no code, let it warm up no code

took it to about 5-6k rpm it popped a p0170 code( fuel tri malfunction bank 1)

then after about 5 min of idling the O2 sensor heater code came back up

and kept coming back after clearing...




so with a solid cel from obd1 p30 ecu to sensor heater with p2t ecu is there something else i should check with wiring besides O2 sensor?

i checked the thermostat ground already and cleaned it

 

well sure as hell it was something stupid just like always my luck

the heater element pin backed out but because it was so dirty from previous deuchebag owner(s) i didnt see it.

no codes so far wtf all this time wasted

big **** you goes to previous owners who didnt maintain this for ****