Replaced my O2 sensor

[Moto Man]

My car has about 165,000 km on it and has had some driveability issues for a while. The idle hasn't been as stable as it should be, and there were flat spots when accelerating. The last time I had it in for service, they said that the O2 sensor was a bit "lazy", but didn't think it was bad enough to be worth replacing. Overall, they thought my car was running quite well for its age.

A new O2 sensor wasn't that expensive, so I got one and installed it myself. I got the NTK 23044 which has the correct connector on it. The correct connector is just a common spade connector. I could have saved a few dollars by buying a universal sensor and crimping a connector on myself.

Removing and installing the sensor is not that hard. The trickiest bit was moving the heat shield out of the way. That may not have been necessary if I had an O2 sensor socket, but I didn't feel like spending money on a tool I'll hardly ever use. Instead I used a 7/8" combination wrench.

The new sensor has fixed my driveability issues. I should have replaced it long ago.

In retrospect, I wish I'd looked into upgrading to a heated O2 sensor. It's not that I'm particularly concerned about emission, but a heated sensor would give me better throttle response when the engine is cold.

My thinking is that when the engine is cold, the O2 sensor doesn't work and the engine runs in open loop mode. The computer meters fuel based on the air flow sensor and other sensors without the benefit of the O2 sensor for fine tuning. That's ok when all the sensors and fuel injectors are working 100%, but I expect that at 165,000 km some of those components are less than perfect. Heated sensors take much less time to get up to operating temperature, allowing the computer to get the mixture right that much sooner.

[240DRFT]

u removed the heat shield to put it on? i didnt have to, but maybe uts cuz i have a s14's header.

[ricebike]

Removing and installing the sensor is not that hard. The trickiest bit was moving the heat shield out of the way. That may not have been necessary if I had an O2 sensor socket, but I didn't feel like spending money on a tool I'll hardly ever use. Instead I used a 7/8" combination wrench.

http://www.autozone.com has a variety of "loan tools" that won't cost u a cent; just deposit to make sure u return it. is there such a thing like that w/ you parts slingers up there?

Quote »My thinking is that when the engine is cold, the O2 sensor doesn't work and the engine runs in open loop mode. The computer meters fuel based on the air flow sensor and other sensors without the benefit of the O2 sensor for fine tuning. That's ok when all the sensors and fuel injectors are working 100%, but I expect that at 165,000 km some of those components are less than perfect. Heated sensors take much less time to get up to operating temperature, allowing the computer to get the mixture right that much sooner.[/quote]open loop based on a preset limits burned into the Car's PC until the 02 sensor is heated enough to kick it into "closed loop"

That's Y I didn't take the AIV system completely off... it's that purpose to introduce more 02 to the cat to heat it up to operating temp faster... I just isolated the tube from the rest of the airbox & put a small cone filter @ the end of it.
Modified by ricebike at 1:52 AM 11/24/2005

[Moto Man]

I didn't think about renting or borrowing an O2 socket. Moving the heat shield took a bit of time but was not really difficult.