Running Rich?

[cucumber]

I've had this recent problem with my car which leads me to believe I have a faulty 02 sensor causing my car to run rich, however, I'd like a second opinion.

On my mad-tyte-raver-blinky-show gauge, I'm reading full rich at WOT and at 10% throttle. I'm getting 15 MPG. I'm smoking black smoke. My plugs are black. I'd say I'm running rich, however, it has not thrown a CEL yet.

Does anyone have an idea?

 

[98TsiAWD]

Have any friends with a scantool? So you can see what voltage readings the o2 is giving off?

 

[GTM]

Originally posted by cucumber
I've had this recent problem with my car which leads me to believe I have a faulty 02 sensor causing my car to run rich, however, I'd like a second opinion.
...
I'd say I'm running rich, however, it has not thrown a CEL yet. Does anyone have an idea?

Just discussing this problem with another member but off list.

Have you checked the temp sensor on the thermostat housing???

I don't have a manual for you car but earlier models have a 2 wire sensor which will cause this problem. This will cause a more dramatic rich condition than the O2 sensor if it has failed completely. There are tests which specify immersion in water with a thermometer to determine resistance values. You might try Vfaq.com or a search here for those values. Do not confuse the smaller "temp sender" which controls the gauge and has a single wire. I've attached a jpg for a 1G if that helps.

My son's 1G went bad some months ago and we replaced it with a unit from Pep Boys for $38 which is about half what the factory wants. In theory these should last for 5 years to meet Federal smog laws so save a few bucks if it tests bad.

Cheers,
GTM

 

[cucumber]

Originally posted by GTM


Just discussing this problem with another member but off list.

Have you checked the temp sensor on the thermostat housing???

I don't have a manual for you car but earlier models have a 2 wire sensor which will cause this problem. This will cause a more dramatic rich condition than the O2 sensor if it has failed completely. There are tests which specify immersion in water with a thermometer to determine resistance values. You might try Vfaq.com or a search here for those values. Do not confuse the smaller "temp sender" which controls the gauge and has a single wire. I've attached a jpg for a 1G if that helps.

My son's 1G went bad some months ago and we replaced it with a unit from Pep Boys for $38 which is about half what the factory wants. In theory these should last for 5 years to meet Federal smog laws so save a few bucks if it tests bad.

Cheers,
GTM

Interesting, thanks for the info. I'll have to check into that.