Error Code P0135

My check engine light came on in my 99 Nissan Maxima SE. I took it to Autozone and they read a code of P0135. The fault code on the machine said something to the effect of: Upstream Heated Sensor Heater circuit fault - Bank No. 1.

I came home and called a Nissan Dealer and they told me one of the O2 sensors was bad. They said it would be about $185 for the part and $85 in labor. Does anyone know which sensor this is and if I could replace it myself? I looked at oxygensensors.com and their parts are all in the $70-90 range for O2 sensors. I'd much rather pay that than $260, if I can.

Any advice?

What year Maxima do you have?

1999

Upstream bank 1 is supposed to be the one nearest the manifold on the left bank (the one nearest the radiator). Make sure it's not just unplugged or a fuse blown. Some even have relays for the heaters.

Since this is a 1999, contact the dealer again with your mileage. Ask what is the emissions warranty for the oxygen sensors. Also ask about recalls or service bulletins relative to your car. You'll need your VIN (serial number). You may get lucky and get it repaired for free.

Thanks. I'm not sure what I'm looking for to be honest. My experience with repairs has been pretty basic... brake pads, oil changes, etc. Perhaps this is too advanced for me and I should just part with the money. You don't know where I could find a step-by-step repair guide do you?

Autozone should have a Haynes manual available. Walmart used to sell some automotive manuals. Stop by almost any reputable repair facility. They'll probably be glad to point it out and give you some general advice.

Check out www.freshalloy.com. Search O2 sensor replacement. Good advice there from Nissan Master Tech.

Is this O2 sensor reachable from underneath the car or from under the hood? I've found the wiring harness connector, I think. Is it the one located directly in front of the engine on the right hand side (from the front of the car)? I'm having a hard time tracing the wiring, it looks like it gets tied in with some other wires on the right side of the engine, then I see what looks like it could possibly be an 02 sensor underneath the jumble of wires that connector runs to. Again, any advice would be most helpful. I just don't want to waste time or money replacing the wrong thing.

I've been told it's out of warranty (I've used my max liberally, wracking up over 85,000 miles). Thanks again for all of your help!

I forgot to mention... I picked up the Haynes manual it looks like it should be helpful... just confused me, because it looked like they were saying it was under the car and I was of the impression it could be changed from above. I'm planning on purchasing the Bosch 13562 o2 sensor. Any feedback on this one? It is the correct one, right?

Now I'm really confused, I read on AllDataDIY.com that the right bank is Bank 1, not the left bank. Does anyone know for sure which bank is which?

I'm having the same exact Code problem. The Haynes Manual WILL NOT help. The photo in the Haynes manual is from an earlier Maxima that only has one O2 sensor. There is no place on the Internet where you'll find info that is detailed to this code. It seems the diagnostics computers and the parts people do not use the same language describing this part.

What I do know is that on my 99SE, there are 3 sensors.

One has a short blue wire and you can change it by popping your hood and looking down to your left, it's there on the front lefthand corner of the manifold.

The next two, you have to jack up your car to get at from underneath.

One has a red wire and is located before the Catallyic converter.
And the final one has a cream colored wire and that's rear one, which mounts after the CAT.


I changed the easiest one (under the hood), and I still get the code. So I guess that's not Bank1 Sensor 1, like I thought.

If you can spare the dough, replace all 3 and save yourself the guesswork.

Bosch sensors here in NJ are going for about $140 at parts stores, and $150 from dealers. You can get them on the net for cheap, which is where I might buy my next ones.

If you come up with any more info, let me know, because this has been pissing me off for a week.

AllDayDIY.com which is from people who make professional service guides diagrams out the three. It says Bank 1 is the right bank and Bank 2 is the left bank. It shows 3 sensors, but its diagram (at least as far as I can find on the web site) focuses only on where the wiring harness is and how to test it. It does not show where the sensors are. Now, in the flow chart for diagnosing the problem it says to go to the section for replacing the component, but for the life of me I find no such section on their web site. I'm assuming if I get the car up on a jack stand I could reach the other one. The left bank harness (according to the diagram is not the one near the radiator, but the other one.

ALLDATAdiy indicated the problem is with the Right Front Heated Oxygen Sensor HEATER. Which, from my understanding is part of the sensor and is replaced when the sensor is replaced. AllDataDIY also indicates that the right front sensor is the sensor with the BLACK cable.