JBrown

Went for a ride with my mechanic today. We were trying to adjust the car with my SMT-6. Took a call to John to figure out how to adjust the A/F. After making some adjustments, the car ran rich but on the computer it showed lean. You can smell its too rich and the car starts bogging. My mechanic says the computor must be getting a wrong signal from the O2 sensor. It is brand new but i did get it at auto zone. So i dont no if it is a bosch. The other thing he said is the stock O2 sensor will not be accurate with no cat in the car. He said there is no restriction on the exhaust and the sensor could be seeing lean. What do you guys think. The car runs great. Smooth and nice power.
One other problem though. Started hearing a clicking under acceleration by the rear passenger tire. Sounds like a branch was stuck under there but no branch. Noise goes away when i am not acclerating. It is very loud when i lug the car.

fast951

John, Are you reading the AFR in the SMT6? If so, you are looking at the incorrect data. Read the instructions I sent you, it discusses which value to read for correct AFR, follow the table in the document. The O2 sensor if fine where it is.

Check you CV joints (both sides).

Chris White

Just an interesting note (does not apply to the case above - John is on top of that) –

You can get a rich smell and a lean reading – if you car is miss firing (ignition) it will dump unburnt gas into the exhaust – you would think that would cause a rich reading – but no, just the opposite. That is because the O2 sensor is reading Oxygen. If you are missfiring the Oxygen is not being used and therefore there is more O2 in the exhaust – resulting in a lean reading by the O2 sensor.

Chris White