My SES light turned on a couple of days ago. It's throwing the PO135 code. I ordered both pre-cat 02 sensors and they will be here tomorrow.

I haven't changed 02 sensors on a maxima, but I have changed one on a honda many years ago.

Do I need to buy a special tool to make the process go smoother?

The one that's throwing a code is the 02 sensor closest to the firewall. Do I have to remove the wheel or raise the vehicle?

Any advice is appreciated.

 

You will need to get at it from under the car so unless you can squeeze under there without jacking it up, it will need to be jacked up. An O2 sensor socket is always nice to have.

 

^ this

 

Is there any harm in not changing the O2 sensors? I just don't have the money to replace them and it has been some time now. Also, where should I order them from? Isn't there someone on the forums that has them cheaper than the dealership?

 

I've been getting crappy mpg's after getting the PO135 code.

I got them from rockauto. I got the 2 precats for about 140 shipped (NTK brand). I think it was fair price.

 

I just got done replacing both pre-cat 02 sensors. Pretty simple swap.

The 02 closest to the firewall was somewhat of a PITA to replace. The biggest issue is the freakin' factory tie wraps. I managed to remove all them, but I couldn't install the new top tie wrap on the metal bracket. I routed the wire away from the header without issues. I think the tie wrap closest to the 02 sensor is the critical one.

I also noticed that the NTK sensors are really small compared to the Bosch OEM ones. Hopefully I won't have any issues.

Thanks for all the advice fellas!

 

o2 sensor wrench will make your life a lot easier lol.

 

I purchased the 02 socket. The issue was the lack of clearance. I took my time and everything worked out ok. My mpg seem to be improving.

 

keep some wd40 handy too... with all the hot/cold exposure, they could get seized.