So after replacing 02 sensors only the fronts they won't clear even when i try to clear them and the rover is stuck in open loop what is the next thing i need to look at i already hear a rattle in my cats at deceleration and don't want to ruin them anymore. Im using a SnapOn code reader I'm not sure which one as i was borrowing it from my friends dealership. i believe it is a SOLUS ULTRA. but when reading live data voltage is there for the 02s but when everything is warmed up it won't enter closed loop. also at idle my temp sits at about 209 degrees is this way to high? All help appreciated i don't want to have to take it to the stealer or a local shop.

 

What exact codes are you getting that won't clear? If they are lean codes then it might indicate a vacuum leak.

209 seems about right for a stock thermostat. It is high for the grey 180 or the motorad though.

 

its a stock thermostat but I'm getting 02 sensor codes ckt no response and heater circuit malfunction

 

Did you buy bosch O2's or aftermarket?
Check all of the fuses (look close at fuse #2 under the hood) start under the hood and then check under the dash.
If all of the fuses look good then use a test light and check the O2 plug to make sure the sensors are getting power

 

They are Bosch with orange connectors. would my code reader be showing voltage if they weren't connected though?

I read on another thread the only other one that i could find where someone was stuck in open loop that they should check some sensor that is behind the alternator and that it should have 300ohms

 

I thought you said you were getting a circuit no response code? How are you reading the sensor with no response? Do you think you could give me the actual trouble code numbers that you are getting.

Are you sure it's not circuit "slow" response, instead of "no" response?

 

If you are getting heater codes, there is either something wrong with the sensors, connections, the wires, or something like that. No need to troubleshoot the lack of sensor data when the heaters are saying they aren't working.

 

Thats why I'm getting so confused at the fact i can get response when the code says CKT no response. its p0304 for the CKT no response. p0135 for the heater circuit. its showing for both left and right sensors

 

Okay this is why I like actual code numbers. I believe that P0304 is a cylinder 4 misfire not CKT no response.

P0135- is for the bank 1 sensor 1 heater circuit malfunction. If both front sensors are getting a heater malfunction then you should be getting a P0155 also for heater malfunction bank 2 sensor 1.

If you are just getting a P0135 than I would try switching the front O2 sensors to see if the code switches to the Bank 2 sensor. If the code switches then you got a bad sensor. An O2 sensor can be damaged if dropped or over tightened so if it is still under warranty then I would just try and get a new sensor and see if that helps your problem.

As for the #4 misfire. Check the plug and wire very carefully for the #4 cylinder to make sure it is on all the way and there isn't a small cut in the wire.

 

its saying it for both 02 sensors so is that what is throwing it into open loop (the heater problem) or is it the miss fire? also why is such a high end code reader showing a misfire as a CKT No response

Basically what do i need to do to get the truck back into closed loop.