P0135 code and question?

[Oldtom]

Good evening - My 2003 Dodge Caravan lit the check engine light. I bought a 15 buck OBD Scanner at Walmart and it gave code P0135. I replaced the downstream O2 sensor and the check engine light is now out. I did disconnect the battery cable for safety while changing the sensor.

The OBD scanner now shows " no trouble codes "

Did I fix the problem or just temporarily reset the check engine light by disconnecting the battery?

Thank you in advance for any advice

 

[Chris142]

Have you driven it long enough for it to run that monitor?

 

[StevieC]

Depends if the emission monitors have completed their check since the repair, It might take a while for the problem to appear again if it wasn't the sensor.

 

[sprite1741]

Isn't 0135 the upstream sensor? If you clear the codes and didn't fix it may take a while before it comes back. I had an 0136, cleared the code and it was ok for a month then showed up again. Replaced the downstream sensor and the code never came back.

 

[FowVay]

The generic P0135 is a bank 1, sensor 1 error code. This would be an upstream O2 sensor. You may have replaced the wrong sensor.

 

[Oldtom]

Good catch on the sensor! The sensor I replaced is in the exhaust manifold and is considered the upstream sensor. My mistake calling it downstream. I have only driven the van about 25 miles so far. I guess the next few weeks of driving will tell.

I do not really understand the whole OBD concept. I would think there would still be a pending trouble code if the new sensor did not fix the problem. Time will tell.

Thanks for your replies.

 

[StevieC]

Pending codes is the ECU aware of a fault (something doesn't look right to it) but it's giving the input time to resolve itself before storing a hard code which is the code you read with your scanner. Advanced scanners can read the pending codes as well.

 

[RF Overlord]

Google 2003 Caravan drive cycle or words to that effect. Follow the instructions and you should be able to tell in a short time whether you actually fixed the issue.

 

[Tomioka]

If the Walmart code reader does not show I/M readiness then it's a bit unsure unless the light does not come back after several drives.

Usually the O2 I/M monitor is done on the first drive after clearing codes or disconnecting the battery and will set the check engine light if it still finds a fault.

 

[vssjim]

P0135 should be upstream O2 heater fault and it will probably come back but as long as it is sensor not wiring or complex problem it is an easy and cheap fix really,

 

[mk378]

Heater faults will typically set a code and light the CEL immediately when they occur.

 

[StevieC]

On Chrysler they check the heater when the vehicle has just been turned off and then will set the code and illuminate the CEL on the next re-start.

 

[Oldtom]

Thanks to everyone who posted. I stopped by Advance Auto today and had them check for pending trouble codes, since they have a higher end OBD scanner. No pending codes and looks great