# Check Engine Knock Sensor Exhaust Gas Temp Sensor



## mc60170 (Jul 13, 2006)

Hi Guys,

Lately the check engine light comes on when I am driving at highway speeds. Also occasionally at lower speeds the engine hesitates a little. I also think my mileage is down.

I ran the ECM diagnostics on my 1994 Altima and got two codes: 

34 - Knock sensor circuit is open or short (this does not trigger check engine)

35 - Exhaust Gas Temperature Sensor is open or short

Should I look at getting these replaced? It looks like the Exhaust Gas Temperature Sensor would be fairly straight forward, but the Knock Sensor is not something I could do.

Money is tight right now some I am looking for some advice on whether to do anything now or just drive and wait.

Thanks in advance,
Marc

1994 Altima GXE
260,000+ miles


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## smj999smj (Jan 1, 2006)

Address the exhaust gas temperature sensor issue first, erase the codes, then check back a couple of days later to see if the knock sensor code has been eliminated or reset. Often knock sensor codes set due to it responding to another problem. As far as the exhaust gas sensor, it may not necessarily be set due to a faulty sensor. Follow the factory service manual procedure for DTC 35 to properly diagnose and isolate the problem to the actual failure, rather than assume it is the sensor that has failed.


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## mc60170 (Jul 13, 2006)

Thank you very much, smj999smj....that is just the kind of information that I was looking for. If it does turn out that the Gas Exhaust Temperature Sensor is faulty, it that I job I can easily do myself?


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