hey guys and gals, im kinda new to honda but im having an issue with my car and for the life of me cant figure it out. first i will tell you what i have.
i have a 96 ex coupe 5 speed, its got a D15B motor. the computer is the stock 96 5 speed. it apears to have all the stock wiring. the check engine light is on due to the code for the o2 sensor. it only has one in it below the header, cant locate a pigtail for the lower one even though the 96 should have one... when i got the car it was having a cooling issue turned out to be the radiator, got that all fixed. but because im shipping this to germany to be safe we changed everything, water pump, hoses, radiator, thermostat and we changed the head gasket.
now my problem, before all this even with the CEL on and overheating the vtec worked perfectly. upon reassymbly i have no vtec. ive ran through all the tests, the solenoid clicks when power is applied, oil level is perfect, operating temp is fine,i cleaned the screen and the solenoid itself and checked for blockage and free movement of the piston inside of it.. checked and rechecked wire connectors hoses and vac lines.all hooked up...i have no clue why after removing the head it wont work. (if i hook a hot wire to it everything works, i hooked a switch too it and drove it and hit the switch at 5500rpm(where vtec used to kick in)) i compaired the gaskets and they were the same, as the parts store showed the same part number for the d15 as the d16 (original motor). what else could i be missing? could it finaly just need to have the o2 sensor addressed? i read that if the CEL is on the vtec will not work . also when i got the car it had no cats and no simulators, header type manifold not the stock type with cat built in....... but like i said the vtec worked before, i have sence added a cat but the CEL is still on and i have no clue, i ran out of time before having to ship the car so im trying to get ideas and maybe parts together before i meet up with my car in 2 weeks so i can fix it. any help? thanks in advance!

 

i was doing some reading and i have no idea if this matters but would the type of engine oil effect the vtec? if the oil was thicker than 5w30 or something? this may be dumb of me but i dont remeber what we put in it..i know i used quakerstate oil....

 

no body?

 

edit error

 

im in kentucky right now and no its not the stock motor its swaped but the computer and harness is stock

 

1) What specific CEL codes are currently thrown? Pull the CEL codes again to see whether any new ones have appeared. Then clear the ECU and see what codes repeat.

2) The problem might be the ECU. Check whether the ECU is providing the proper voltage to the solenoid when VTEC should kick ON. Is the VTEC pressure switch working?

 

no new codes just showing the code for the o2 sensor, we cleared it with the handheld code reader and with the battery but it comes back...only that o2 code.....which im not sure whats up because it worked fine before with the cel on.......will have to check connections again, but if i hook power to the green/yellow solenoid wire it clicks..im not sure what else i could have done or didnt do when we put it back together but i do know it should have an o2 sensor AFTER the cat and sence the manifold/cat was removed for a header and i had the high flow cat put in below the trans, should the o2 sensor have been moved too? and would the o2 sensor efect vtec operation?

 

Are you saying that neither O2 sensor is installed? I'm pretty sure not having a primary O2 sensor will prevent VTEC engagement.

The ECU supplies power to the VTEC solenoid. Is it properly doing this? Is the VTEC pressure switch working?

 

primary o2 is there and yes the switch seems to have resistence i checked it based on this: https://www.hondacivicforum.com/foru...ad.php?t=73905
i have no clue all plugs and wires are hooked up. i know i must sound stupid but i really dont know anything about vtec as this is my first ever honda or import of any kind.

 

thanks for the time your putting in, i appreciate it