Voltage reading on Sec. 02 but I only have Primary 02 Help!!

Falcon · Post by **Falcon** » Thu Jun 02, 2005 4:39 pm

I am getting 2 Cels on my K20a EG swap. VTEC System mafunction (P1259); and Primary Heated Oxygen Sensor (P0135). I have the Primary sensor hooked up but I notice no voltage reading on the datalog but I am getting a reading on my Secondary O2 sensor. The lambda reading is constantly at 14.7. Please help.

Falcon · Post by **Falcon** » Thu Jun 02, 2005 4:44 pm

I just checked my datalog and got the following:

O2 - 0.00V
O2C - -37.0mA
SO2 - 4.10V
AF - 14.70:1

I hope this helps

Post by **Hondata** » Fri Jun 03, 2005 9:05 am

With the wideband o2 ignore the voltage - the lambda is the only thing that matters.

P1259 - disable the VTEC oil pressure switch (you probably have a JDM ECU and/or harness).

P0135 - check your o2 wiring as per http://www.hondata.com/techk20wiring.html The o2 sensor heater relay wiring as per the diagram is the only way which will work correctly.