Oxygen Sensor Question

chadder1313

Registered User
Do oxygen sensors have anything to do with timing? If so what could a possible bad oxygen sensor do with the timing?
 
So faulty oxygen sensors could not lead to detonation right?

Yes, they could.

The O2 sensors are used amongst other things to verify that there's enough fuel, but not too much, for the curve programmed into the ECC.

A faulty one that reads rich could cause the car to lean out too much.

Don't know how often they fail that way, but it's very possible.

I'd first make sure the MAF sensor is cleaned up (THAT being off can cause the ECC to screw up on the fuel mix and cause quite some detonation in NA cars ... bet it's the same in SCs, too.)

RwP
 
They could if the fueling was being leaned out enough. O2 sensors can cause either rich or lean conditions.

Vacuum leaks can also cause false readings and detonation as well.

Fraser
 
Not likely at wot. They are to keep the AFR at 14.7:1 in closed loop/part throttle.

Actually, on a stock tune it can affect WOT fueling as well. The adaptive learning which is based off of the O2 sensors, is applied to WOT conditions, unless it is tuned not to do that.

Fraser
 
Hmm interesting. Im getting some detonation at WOT and im assuming it could be the oxygen sensors. MAF was just cleaned because that was my first guess as well. Vacuum lines are all good as well.
 
Yeah its on the SC. No i havent pulled the codes partly becuase i really am not positve on how to do it.

Easiest way that also is the cheapest (any cheaper isn't as easy, any easier isn't anywhere near as cheap) is to use something like the Innova 3145 - such as sold here: http://www.handsontools.com/Equus-Innova-3145-OBD-I-Ford-Scan-Tool_p_5574.html

That will give you the scan codes as 2 or 3 digit numbers, which you can then look up in the owner's manual.

There's also the "short two wires" method where you count the blinks on the "Check Engine" light, up to such devices as this one: http://www.handsontools.com/Equus-Innova-3120-CAN-OBD2-1-Code-Reader-Kit_p_5572.html and up into the $5,000 range (why I said "cheapest and easiest" for the 3145 ... )

RwP
 
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