O2 Sensor

[cfj610]

I upgraded a GREAT running 87 R10 (2WD) 305 to a 350 and have had rich fuel issues ever since. Only other additions is the mild RV Cam and Headers

We "think" it's running rich due to the single wire O2 Sensor being installed just behind the headers on the drivers side causing the sensor to not see enough heat and operate properly since it's not near the motor where it belongs.

My question is: is it possible to install an incorrect resistor on the end of the O2 wire faking a correct reading resulting in allowing the computer to lean the fuel ratio and run better?
(and plug the bung). And if this DID work, would it likely run poorly until warmed up?

I'm totally spitballing at this point and running out of ideas. Also looking at installing this Stage 1 Computer Chip Module https://www.summitracing.com/parts/JET-28703
Any advice is appreciated and Thank You!

 

[Ricko1966]

No using a resistor and no O2 will not work. I could tell you how to input your own signal,but it would constantly change,you would constantly have to monitor it and compensate. Are you running a factory heat range thermostat? If you are running a cold thermostat the cts is going to be addingbfuel thinking the engine is still cold.If the O2 sensor never gets hot enough you will never get into closed loop.Go back to your first thread and follow the advice there,until you are getting a hot o2 sensor and into closed loop there is nothing else to do.

 

[Edelbrock]

Maybe install an O2 sensor that comes from the factory with a heating circuit? So the sensor heats itself up on its own. You would have to get one that has the same performance values though.

 

[edgephoto]

You can use a heated O2 sensor. You will have to wire up the heater circuit but that would not be hard to do.

 

[Ricko1966]

I'm an amature gynecologist,and this is an old post,I'm sure his problem is fixed. O2 sensor was not his problem. O2 is not in play in open loop. Most likely the problem is trying to run a 350 with a cam on stock 305 engine management. Also possibly bad CTS or excess fuel pressure. But not O2 sensor. Where's the guy that prefaces everything with I'm a field engineer for a major automotive company when we need him?

 

[bucket]

I'm an amature gynecologist,and this is an old post,I'm sure his problem is fixed. O2 sensor was not his problem. O2 is not in play in open loop. Most likely the problem is trying to run a 350 with a cam on stock 305 engine management. Also possibly bad CTS or excess fuel pressure. But not O2 sensor. Where's the guy that prefaces everything with I'm a field engineer for a major automotive company when we need him?

I just came across this thread and was reading along, thinking the same thing. The O2 sensor wasn't the problem, it was the cam swap on stock tuning.