Nuther Howell FI question

[thescot]

Still getting around to things with my CEL last week. It was suggested the 02 sensor is a candidate so I figures for $40 I'll replace it. The confusion lies in which one as my 83 needs to pass ca smog checks. Howell says the Ca version needs a heated 02 sensor and gives the GM number for it,which by all accounts I can pin down says is a 4 wire sensor. My system is using a single wire plug or "non heated" with no unused wires left hanging around. Hows this gonna work?

 

[ThisGuyUKnow]

Still getting around to things with my CEL last week. It was suggested the 02 sensor is a candidate so I figures for $40 I'll replace it. The confusion lies in which one as my 83 needs to pass ca smog checks. Howell says the Ca version needs a heated 02 sensor and gives the GM number for it,which by all accounts I can pin down says is a 4 wire sensor. My system is using a single wire plug or "non heated" with no unused wires left hanging around. Hows this gonna work?

Just get a one wire o2 sensor. From what i understand the heated style o2 just gets to its ideal operation faster than the one wire one. once the jeep is to operating temp there should be no difference in function. Just make sure she is warmed up when you go to the smog station.

 

[Shifter]

He is correct

 

[Torxhead]

Looking at the Howell Jeep CJ instructions, the GM p/n is GM25312184. I used the N.A.P.A. part for that and it is a 3 wire. As I recall the wire colors are different, but it does work.

 

[jdarg]

Just get a one wire o2 sensor. From what i understand the heated style o2 just gets to its ideal operation faster than the one wire one. once the jeep is to operating temp there should be no difference in function. Just make sure she is warmed up when you go to the smog station.

There's more to it than how quickly it gets to temp (and thus enters closed loop A/F.)

A heated o2 will tend to stay in closed loop in situations where a non-heated O2 sensor will not, i.e. when idling, using headers and the O2 is further down the pipe vs. stock. Headers wreak havoc w/ one wire O2 sensors, as do some "custom" installs where the sensor is too far away. If this is a AMC 258 i6 / 4.2l manifold and you are using the o2 bung in that manifold thats a few inches from the head, its not a concern. On a v8, using headers/exhaust manifolds, its definitely a concern, and 1 wire often won't work right in these situations.

I would go to a 3 or 4 wire heated o2 myself. There isn't much to it all you need is a switched 12v and ground to run the heater element, and running a dedicated o2 sensor ground is a good idea too (i.e. a 4-wire sensor.) You don't want the system dropping into open loop when it isn't supposed to once it is warmed up. It will cause all sorts of goofy driveability issues. A 3/4 wire sensor should guarantee that.

 

[Torxhead]

If you have a Howell setup with a one wire o2 sensor, I am pretty sure that you do not have the Ca. smog legal kit. You can call Howell up and get the required items.

 

[ThisGuyUKnow]

There's more to it than how quickly it gets to temp (and thus enters closed loop A/F.)

A heated o2 will tend to stay in closed loop in situations where a non-heated O2 sensor will not, i.e. when idling, using headers and the O2 is further down the pipe vs. stock. Headers wreak havoc w/ one wire O2 sensors, as do some "custom" installs where the sensor is too far away. If this is a AMC 258 i6 / 4.2l manifold and you are using the o2 bung in that manifold thats a few inches from the head, its not a concern. On a v8, using headers/exhaust manifolds, its definitely a concern, and 1 wire often won't work right in these situations.

I would go to a 3 or 4 wire heated o2 myself. There isn't much to it all you need is a switched 12v and ground to run the heater element, and running a dedicated o2 sensor ground is a good idea too (i.e. a 4-wire sensor.) You don't want the system dropping into open loop when it isn't supposed to once it is warmed up. It will cause all sorts of goofy driveability issues. A 3/4 wire sensor should guarantee that.

My corvette tpi wiring from a 350 came with a one wire o2. I accidentally ordered a three wire. How do you know which wire is which for the acc wire ground wire and sensor wire

 

[Torxhead]

My corvette tpi wiring from a 350 came with a one wire o2. I accidentally ordered a three wire. How do you know which wire is which for the acc wire ground wire and sensor wire

On the three wire oxy sensor, the wires are for the sensor output which is .1 to .9 volts variable as the engine is running, the heater element and the ground. I would think a resistance meter would work to find which wire goes to the sensor tip.

 

[thescot]

If you have a Howell setup with a one wire o2 sensor, I am pretty sure that you do not have the Ca. smog legal kit. You can call Howell up and get the required items.

That would not be a good thing, I do have the under hood Ca legal sticker but who knows. Its been smogged OK for the last decade here in ca with no problems. But....I can see things that dont fly for the visual so I want to get it all correct plus find the source of the one CEL weeks ago.

 

[thescot]

Ok...apparently Im going blind as It does have a 4 wire sensor. Good is its a Ca FI setup, bad is Im going blind I recon