Chrysler Repair: 2001 Town & Country: code 0135 O2 sensor, torque wrench, box end wrench

Question
Hi,
I have a 2oo1 Town & Country mini van. The engin light is on for a couple of months now. I took to a mechanic and had him read the code, he told me the code is P0135. One of the causes for this code is the O2 heat sensor but i am not sure which one? is it hard to replace the sensor and how much a dealer will charge for replacing it?

thanks

Answer
Hi Mike,
The 0135 points to the right bank upper sensor which is on the side of the engine closer to the fire wall and mounted on the exhaust manifold, right in the middle above the exhaust pipe. It is not hard to replace, once you get to it (which I can't off hand tell you for your particular engine), but you will want to soak the threads overnight with penetrating oil and then heat up the engine before unscrewing it. It looks like a spark plug except with four wires on the tip. These wires are fragile so you will need to use a 22mm box end wrench to remove and replace it, rocking the body back and forth to free-up the threads. The new one will come with some anti-seize compound to apply to the threads. It is torqued about the same as a spark plug. It is not crucial to use torque wrench if you know the feeling of a spark plug (about 20 foot-pounds). A special deep socket with a slit for the wires is otherwise needed to use a torque wrench, and that adds to the cost. So you can probably forgo that cost.  
I can't tell you how much a dealer/shop charges, as I haven't had it done that way. But I think you should be able to do it yourself. You could call around to shops in your area and make inquiry.
Roland
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