[perley03]

I just started my Jeep to go to work, and after about 5 minutes idling, it started skipping. I went out and looked at it and the check engine light was on, so I grabbed my scanner and it read P0135- 02 Sensor Heater Malfunction; Bank 1. But the funny thing is, once that light was on, it doesn't skip. Does this mean that the front 02 sensor is bad? I have a small exhaust leak at the collector, but I didn't think it would bother it that bad. Any suggestions?

[perley03]

How do you test a bad 02 sensor?
Would an exhaust leak before the sensor cause it to throw this code?

[Fox Fader]

Originally Posted by perley03

How do you test a bad 02 sensor?
Would an exhaust leak before the sensor cause it to throw this code?

I don't think so., I 've never seen that happen. My friends TJ has had a crack in the M-fold for a while now.

As far as checking the O2, I've never heard of that either. Go to www.oxygensensors.com and order a new one.

Maybe the ECU once realizes the O2 is bad it goes to a base map which will make the engine run smooth, but not be able to make the appropriate air/fuel changes via the O2. Make sense?

Troy

[perley03]

Originally Posted by Fox Fader

I don't think so., I 've never seen that happen. My friends TJ has had a crack in the M-fold for a while now.

As far as checking the O2, I've never heard of that either. Go to www.oxygensensors.com and order a new one.

Maybe the ECU once realizes the O2 is bad it goes to a base map which will make the engine run smooth, but not be able to make the appropriate air/fuel changes via the O2. Make sense?

Troy

Ahh, got ya. But if exhaust is leaking before the 02 sensor, wouldn't that throw off the a/f ratio as well?
I just looked, and its the exhaust manifold thats leaking, it has a crack inbetween 2-3 cylinders. I just replaced one on my Dakota before I traded it, and had to pull the head to remove the broken studs...

[Rivi]

the 02 heater circuit is open,either one of the wires shorted or the fuse is blown or the heater element in the 02 went bad.These are heated 02 sensors,that means there is a heater circuit built in to them to preheat them up to temp.The pcm moniters current flow in the heater circuit and if it doesn't see any it sets this code.

[Fox Fader]

Originally Posted by perley03

Ahh, got ya. But if exhaust is leaking before the 02 sensor, wouldn't that throw off the a/f ratio as well?
I just looked, and its the exhaust manifold thats leaking, it has a crack inbetween 2-3 cylinders. I just replaced one on my Dakota before I traded it, and had to pull the head to remove the broken studs...

Probably not, the mixture of the exhaust is still there, the O2's don't read volume just the amount of oxygen in the given mixture.