Nissan: 2001 Nissan Maxima - 2 problems, nissan maxima, o2 sensors

Question
Hello A. Torelli -

I have a 2001 Nissan Maxima.  My husband is changing both belts as we speak.  Is there a belt diagram or any secrets about some bolts near the belt that is near the water pump?  He knows that the top bolt must be loose before removing the one belt and did that but wonders if there is another bolt that he must loosen for the belt near the water pump?

2nd - The dealer said the engine light is on because the O2 sensor is bad and possibly the cadilidic converter.  They said they always start with the O2 sensor and 99% of the time it fixes the problem.  I believe there are 3 O2 sensors on the car - so how do i know which one to change.  My husband bought a universal O2 sensor at Advance Auto and is going to change that too.  He assumes it's the sensor right before the converter but isn't sure.  Any suggestions?

Thank you!
Jamie

Answer
01 Maxima should have that funny looking bolt that moves the tensioner. They always freeze up and the only way to loosen them is to remove them and heat them up with a torch. The other belt (power steering) is loosened from under the car. You actually have to tighten to loosen and loosen to tighten. Its hard to get to and tricky. There are sveral 02s. You have to look at the data stream or read the codes. Usually it will say bank one, sensor one. I like to take a snap shot of the O2 in action before I replace them. I would not suggest an aftermarket or universal 02. Use and OEM part