I checked a oxygen sensor reading last night and it was fluctuating between 300 and 450mv. I never went up. The car has been warmed up.

What does it mean? I ahve an AFPR set at 42Psi with vacuum hose attached.

i have repleced this sensor 1.5 year ago with the OEM replacement called NIEHOFF.

Can anybody suggest something.

Should I install my old sensor and see what happens?

Thanks.

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89Iroc, 305 TPI, WC T5, 3.08 Posi, Headers, Hooker Y-Pipe, 3 inch over the axle, Flowmaster 80, No Cat, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, All free mods,

 

D,

Either the exhaust is very lean, or the sensor is not getting hot enough, or the sensor is failing. It would be fairly easy to swap back to the old one as a comparison.

To make sure you are not running artificially lean, check the A.I.R. system diverter valve and check valves. A leaking diverter can dump excess air into the exhaust, causing a false lean reading of the O2 sensor (low O2 voltage).

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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
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Thanks Vader for the reply.

I have removed the AIR crup long time ago so it would not be it.

Would't the ECM stay in the open loop if the oxygen sensor was not warming up?


I am going to put my old one in to see what happens.

Maybe is not warming up because of headers.



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89Iroc, 305 TPI, WC T5, 3.08 Posi, Headers, Hooker Y-Pipe, 3 inch over the axle, Flowmaster 80, No Cat, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, All free mods,