engine dies at idle

[jeff]

The engine will not idle.

headgasket just replaced due to severe overheating
new timing belt
new idle control valve
no vacuum leaks
adjusted cold idle valve per the video
check engine light on all of the time.
code 41 which is o2 sensor heater failure.
timing ok
cleared code but will come back on immediately if accelerator is depressed after starting
runs great otherwise

my question is where else to look for the solution and would the o2 sensor cause the idle issue.

Topic

[Charles]

The computer uses the O2 sensor to determine how much fuel to deliver to the engine. The O2 sensor must have heat to work so the heater failure will cause the sensor to fail. Most likely will fix the problem.

[none]

Unless that O2 heater circuit is shorting out another circuit, the car should still idle. The point behind the heater circuit is to get the car into closed loop operation faster and maintain closed loop when the engine isn’t making enough heat to sustain the temperatures needed for proper O2 sensor operation. This pretty much accounts for engine idle time. But there is always a time that the PCM has to ignore O2 sensor input and that’s when they’re not hot enough to accurately report O2 content. This is when the PCM is in open loop; and the engine still idles.

While the O2 sensor definitely could be a problem, it isn’t necessarily going to be the problem.

[jeff]

Thank you for the replies. I have an o2 sensor coming and was going to replace it anyway. i’ll post back my results.

[jeff]

so the o2 sensor corrected the problem. the end of the sensor was totally burned away. runs great now.

[Author]

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