BAD O2 Sensor ????

[Don 944 LA]

With the O2 sensor disconnected and DVM connected...
It reads .003 Volts and fluctuates slightly as the spring in the AFM is moved...

I wanted to test it before I changed the $#%^ O2 sensor.

Also, where should the arm on the AFM be at Idle ???
and is this a good way to set it to spec.


Thanks again for any info

Don

[Lawrence Coppari]

Do a search on this list about O2 sensors. Someone referenced a link about what the thing should read. Yours sounds very low to me by a couple of decimal points.

[will944]

Don....I never get tired of looknig at your avatar or whatever they call em.....

Thanks

[tobster1911]

I was told by a Porsche shop that the O2 reads from 0 to 1 volts with normal at .5 volts. Check FRWilks site for more info on the O2 sensors.

[tobster1911]

I was told by a porsche shop that normal was 0.5 volts on a 0 to 1 scale. Also check FR Wilks site for good info on O2 sensors.

[Don 944 LA]

Originally posted by will944
Don....I never get tired of looknig at your avatar or whatever they call em.....

Thanks

No Problem
here's ahint : right click on the image and select " set as desktop item " and you will ALWAYS have it to look at.


I did get most of the info for the O2 sensor from FRWilks site.
I bought a Ford Aerostar van O2 sensor.
I've been trying all day to get the MF'er off.

I do have the FQS in position 4. After I change the O2 sensor I'll put it back and try the Smog check again.

The F'ed up part is I have a HUGE fixit ticket for registration etc...
I can't get it registered till I pass the smog.

I also replaced the DME Temp sensor.
I should be covered now, I hope.

Don

[Don 944 LA]

Here's the original saga.

HELP !!! Failed CA Smog have #'s


Don

[Zero10]

Just a thought, but is the sensor hot when you are testing it?
If it hasn't warmed up yet, the readings will be very low.

[Don 944 LA]

Originally posted by Zero10
Just a thought, but is the sensor hot when you are testing it?
If it hasn't warmed up yet, the readings will be very low.

Yep
I left the heater connected and let it warm up considerably.

Thanks for the input

Don

Oh by the way, I still don't have the damn thing off.
I hit it many times with PB Blaster, lettin it sit overnight.
I could see that the unit was starting to twist instead of coming off.

[latunluvr]

I used to be able to pull the error codes on my car by stepping on the gas (all the way down) for 2 seconds and turn the key to the on position. The check engine light would flash any error codes concerning defective items in the emission system, including the O2 sensor. I think the 944 Hanes manual might contain the emissions error codes, and whether or not the sensor is reporting full lean, full rich, or not reporting at all. Don't have my 951 anymore but it's worth a try.

[Don 944 LA]

Originally posted by latunluvr
I used to be able to pull the error codes on my car by stepping on the gas (all the way down) for 2 seconds and turn the key to the on position. The check engine light would flash any error codes concerning defective items in the emission system, including the O2 sensor. I think the 944 Hanes manual might contain the emissions error codes, and whether or not the sensor is reporting full lean, full rich, or not reporting at all. Don't have my 951 anymore but it's worth a try.

I DO NOT think I'll do that.

[latunluvr]

You don't actually turn the car "ON"! you just turn the key to the "ON" position without engaging the starter. It's by design and it was a requirement that all US cars be equipped with some type of sequence that displays the error codes on the dash lights for emissions related items. It won't hurt your car since the key is off when you step on the gas, then just turn the key, WITHOUT engaging the starter, but turn it into the "ON' position.

It seems like you took it a little different than the way it's supposed to be done. Since this is Porsche site, I ASSumed everyone would be able to figure out what I was talking about without having to explain to Darrel and his other brother Darrel, not to actually "START" the car with the pedal to the metal!

DUH!

[Britwrench]

You can only obtain the fault codes on certain cars that have a "check engine" light (CEL). 944s don't have one and the early "blink code" fault reader is a little bit more than totally useless. During the 1989 model year 944S2 and Turbo models were updated to use the diagnosis plug for the Bosch KTS300 (Hammer). While obtaining the codes for applicable vehicles with a CEL using the throttle pedal method does work (Second hand report as I've never used it as we have the diagnostic tools). Unless it can be confirmed that the fault exists and the code is correct, you are no further along actually diagnosing and repairing the fault.