I'm running a 95 sohc vtec block w/ 97 sohc vtec head. Ever sence the head swap I have been getting engine code 1 02 sensor. I replaced the 02 sensor with a brand new one and I still get the code, immediately after the car is started. I know I have a vacume leak at my throtle body temperarily, could this trigger oxygen content engine code 1?
-Derek-
.Afterdark.

 

I what car are you running this swap??

 

I'm not positive if that would trigger a code, but get the vacuum leak fixed asap.

 

If the light comes on a few seconds after you start the car- there is probably something wrong with the heater circuit.

 

you try resetting the ECU?

 

OBD1 ECU?

I know, with OBD2...if you have a heater circuit problem you will get code 41(for the primary O2 heater)....and you will not get code 1 until you get the code 41 fixed first.

You shouldn't get a code 1 until you take a few fully warm trips in your car, unless the wiring is messed up.....that is pretty much the only way to get a code 1 right after startup.

 

Since the 02 sensor is brand new I dont think there is a problem with the sensor its self. The only thing left is the heater circut itself. But if something was wrong with this circut how would I check for it, volt meter or something? Could it just be a faulty wire or something?
-Derek-
.Afterdark.

 

I assume you are running an OBD1 ECU....if you got a new sensor it must be the wiring...for either the heater, or sensor. OBD1 doesn't have different codes to seperate the two different problems.

 

You might want to double check to make sure you've installed the wiring harness correctly. I've noticed that there are two circular wiring connectors that lead to the bottom of the intake plenum. One hooks to the Fuel Vapor return and I think the other goes to the PCV... Regardless, mixups like this could lead the diagnostics to think you've got a vacuum leak. Doublecheck EVERYTHING!

-T