Ok so I have to take emissions by the end of Sept. I am throwing code p0135. I have s2s2 cams, s2 intake manifold, itr pistons, smsp header and other bolt ons tuned on neptune with a p28 obd1 ecu. When i plug in my obd2 ecu I throw this code. I tried using one of my friends o2 sensors, this did not work. I have searched but I could not find anything helpful. Anyone have any ideas?

 

135 is int he heater, chck if there is 12v there and the ground is good and make sure the heater is ok in the sensors you are installing.

in the neptune, they may have the the heater disabled.

 

Yes P0135 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Heater Circuit Malfunction. That is the code and when i switch from obd1 ecu tuned on neptune to my stock obd2 ecu it throws the code.

 

neptune probably has the heater disabled. we do that on the hondatas we run in open loop too.

 

ok so why would this matter if im running my obd2 ecu? i just dont understand?

 

bump anyone?

 

he's saying that the reason the OBD1 ECU doesn't throw the CEL is that the CEL is disabled in the neptune program.

are you running an O2 sensor? narrowband or wideband?
If you have a standard narrowband O2, the heater has died or the wiring is bad.

If you're running a wideband all the time (which has no ability to have a normal heater element) a $1.29 radioshack part (#271-153) soldered into the OBD2 ECU and the CEL will be gone.

 

I have the stock o2 sensor in the header.