whats a Front Secondary HO2S Heater Circuit

[austrian type-R]

hi!

my friends 1996 euro NSX with an US Acura NSX ECU throws cel number 65. The manual does not show a cel number 65. I told him to look at NSXprime what code that is.

What is a P0161 Front Secondary HO2S Heater Circuit Malfunction (Bank 2 Sensor 2)?????????????????????? What does it do?

thanks

 

[Briank]

The second O2 sensor for the front cylinder bank (after the cat) is bad and needs to be replaced.

 

[austrian type-R]

euro NSX only have 1 O2 Sensor per Cylinderbank.

Now I understand Euro NSX does not have a # 65 code.

 

[ftuhy]

At least for North America, my '96 has 4 O2 sensors equipped with the heaters - its a 4-wire sensor instead of a 2-wire design. The heater gets the O2 sensor into its operating range sooner so the engine operates at the proper fuel mix sooner. While the idea is sound, Honda had reliability issues with the initial sensors, so much so that for 3 years of production (I think '95, '96 & '97) the US emissions warranty was doubled to 14 years.

So, if your NSX doesn't have heated sensors, your ECU is confused. But, if it does, then the failure is not uncommon. It also means that the car may run fine, but will take a little longer to get into the proper operating region during warm-up. However, when mine failed, the ECU disabled the traction control at the same time so I had to go a little easier on the throttle at times.:biggrin:

Frank
'96 NSX-T