Do I need an O2 sensor?
 

Lately I've noticed that my fuel economy is getting pretty bad. There is also a coating of carbon soot on the inside my exhaust tips that can be wiped off with a finger. And the (under boost) knock counter has stayed at 0 for the last 4 or 5 tanks of fuel, but I guess that is a good thing. All of this indicates to me that the car is running too rich. Others (non-porsche people) have told me that the most likely cause, if the exhaust pipes are sooty, is a bad O2 sensor. Am I correct in assuming that everyone here is in agreement with that?

Since I don't have a lift, I don't do much under-the-car work, and I don't know exactly where the sensor is located. But I assume it has to be accessed from underneath. Is getting to it & changing it a relatively easy job (the underpanels are already off)?

you know that A/F wideband i was talking about? :)

Not that hard to change, its located on the crossover pipe right as it goes into the hotside of the turbo. In my opinion easier to change than the n/a sensor.

Yea, I know that A/F wideband you was talking about. But the cost AND hassle vs. benefit factor has still not (yet?) tipped the scales in favor of it for me. I'm getting pretty darn lazy these days! Plus, the cold weather is starting to set in around here, and I don't have a garage.

At least it's good to know the the stock sensor is an easy change (i.e. very low "hassle factor"). Gotta do it soon though - I just noticed my plugs are starting to foul out.

What is the NGK# to use? I think I will give them a try.

Never mind - I found the # - BPR6ES (normal heat range), and BPR7ES (one step colder). Considering the point we are at in the annual cycle, where on the planet I am located, and the fact that my engine temp gauge barely makes it out of the "white" zone, I will probably opt for the 6's now, possibly going 7 in the spring.

A good "inbetween" range is using the non-projected tip plug:

BR6ES

They are a little colder then the normal BPR6ES, but not as cold as the BPR7ES...


-Rogue

I already purchased the BPR6ES's, but I would like to try the BR6ES's, at some point. Thanks.

Anyways, I just discovered the problem. The O2 sensor was disconnected, probably because the connector was not properly secured in the holding clip. But since I don't know how many miles are on it, and the fact that a new one has already been purchased, I am still going to replace it.

Hi Wildman, When you replace the 02 sensor, drop a weighted string down to tie on the new 02 wire to pull it back up. Makes life easier.

Cheers,
Larry

Thanks for the tip. I probably would have been swearing for quite a while before thinking of something like that.