Heated O2 Sensor

[silverbullet]

Does anyone know which heated O2 sensor i should get? I have taken all the emissions off my car but maitained the stock carb on a Elbrobrock performer intake without egr. I have long tube hedman headers and I put my O2 bung in the exhaust pipe right after it connects to the header. Based on many of the threads in this forum I need to put a heated O2 sensor because the exhaust will be too cold by the time it passes the sensor and then I would get a check engine light and my ar would run too rich. Well all of this is true so does anyone know which heated O2 sensor to get and any instructions on hooking it up.

Thanks
Bill

 

[gedmeyer]

I am interested in this as well. I've got hooker sidepipes and have noticed that the car is running rich.

Any help would be great!

 

[Nut]

I drilled my stock O2 sensor into the collector on the left full length header and never have had a problem with the O2 sensor sending faulty data.


........ nut

 

[Moser28]

I am in the same shape. I just had a bung put in the header and decided to get the heated O2 but I'm not sure how to wire it up either. This is a 4wire Bosch 15732 universal heated O2 sensor.

 

[Peer81]

Well, I don't know the 4 wires but I think you can hook it up to your choke wire. When cold you have power and when hot no power. I don't know for sure but sound good to me

Groeten Peter

 

[LannyL81]

I had this problem with the Hooker Sidepiper headers/exhaust setup. Since our '81's do not have a computer to turn on and off the heater circuit to a 4 wire O2...need to have one with the highest resistance in order to keep current demand low. I found a Denso 2344209 has 15.7 ohms...whereas most others are in the 5.1 to 6.0 ohm range.

Now this will draw a steady 0.765 amps, so need to use around a 18-16 gauge stranded wire for the heater wires. I was going to put additional resistance inline with mine to keep the current lower instead of trying to add a relay or switch to turn off/on the heater current....just too much trouble.

I ended up tapping into the +12v ignition at the distributor and then to an intake bolt for the carb linkage bracket. I run the heater at full at all times. Now this may reduce the life of the O2 sensor, do not know yet.

Wires coming out of a four wire O2 sensor are:
2 black - heater
1 white - ground
1 blue - signal

I cut the 2 wire connector off of the original O2 sensor and crimped this onto the blue and white wires of the 4 wire and then added an additional 2 wire connector for the heater lines.

Sure is nice not to have eye stinging rich exhaust anymore...and no Check Engine Lite either.

Hope this helps.

 

[Moser28]

Ok great. Now all I need to know is which wire is the sensor coming from the car's harness. I know one is the sensor and the other is the ground? I am going to have to cut the connector off and splice everything in...I just don't want to do it backwards. The two wires from the harness are pink (which could have been red) and brown. Thanks for all the info!!!!

 

[o.j.]

I just got hooker sidepipes too. I was planning on just welding the bung on the back side of one of the header pipes, closer to the head....any reason this won't work?

I know I will be reading just one pipe rather than a combination of 4...but is that a big deal?

thanks

 

[RC81]

I was wondering - what is the advantage of a heated sensor?

 

[LannyL81]

To find out which wire is which on the original 2 wire O2 sensor, just use an ohm meter or continunity checked. On my 2 wire, I could see which one was connected to the O2 sensor body (ground) and then follow it back to the connector.

As far only getting the reading from one header tube; might be a problem in timing and heat. Timing due to the time between exhaust pulses for that cylinder and also cooling-off in between pulses.

I put mine in the left sidepipe header collector.

An O2 sensor needs to be at about 600F to work. The heated O2 sensor heats-up the sensor element so that it works faster and in the case of headers with individual tubes...keeps the O2 sensor working as the exhaust temp drops by the time it gets to the collector enough to shut off the O2 sensor output. If a 2 wire is replaced with a 4 wire...the only benefit would be the CCC would go into closed loop a bit quicker...maybe a minute at most would be my guess.

 

[Moser28]

I got everything wired up tonight. The car started on the first try. It's never done that when its cold, especially after two weeks. I don't smell the gas like I was before so it must be working. Next, I will install the check engine light that was removed from the car and start reading codes. Thanks to all that gave info...it made the job much easier!!!