Where to put O2 sensor??

[kaiser715]

I am running a cheby 350, rams horn manifolds, separate pipe off each manifold straight out the back. I have an air/fuel ratio guage on my CJ, and got the same type gauge for the 715. It runs off a single wire O2 sensor.

With the dual exhaust, how should I mount the 02 sensor? Just on one side or the other, or should I add in a crossover pipe and put it there? Or would the proper way be to "Y" them together to a single pipe, then spit again?

[kwai]

Or would the proper way be to "Y" them together to a single pipe, then spit again?

Don't really know how spittin' is gonna help. But hey man, whatever floats yer boat.

[brute4c]

Tech in the tech forums please.

[amphi]

Well! If the sensor is used for the ratio gauge only to simply monitor the gases. I would consider two O2 sensors one in each side with a selector switch. If things get out of wack at least you'd know which side it's coming from.

Jut a wacky idea!

[moosejr]

Well, if you are just after general information, you could run a single one to either side and it wouldn't make a difference, as it isn't going to effect how the engine runs. If it was providing feedback to a computer it would be different. As far as putting in a cross-over, Y, or whatever. You will generally get an improvement in performance with an equalizer pipe between dual exhaust pipes, ..just how much you would see on these trucks would really depend on your setup. The concept is that it improves scavenging of exhaust by equalizing the exhaust pulses.

[randyscycle]

Since an O2 sensor has to see at least 600 degrees to even work, as close to the manifold as possible is the best place. If you were to use a heated (3-wire) O2 sensor it wouldn't be as big an issue. That is what most systems use further downstream in front of and behind the CAT to monitor its performance.

You'll find that with an older engine, at idle the O2 sensor will probably drop out anyway, then re-light at about 1500 RPM or higher. just the nature of the beast with a carburetor.

Since its not controlling the air fuel ratio, only monitoring it, you'll have to put it in one side and get a reading there only. The dual sensor/switch idea is the only way to get both sides information, or a second monitor.

I am running a single heated O2 on my 396 for the fuel injection and it works fine at idle in the Left front pipe about 1 inch below the manifold collector. No problems to report as of yet.