the Walnut Diary

Ruby has been running like a dream since the OEM ignition coils went in.  Then this week she popped a Check Engine Light.  P0050.  Bank 2, Upstream Oxygen Sensor, Heater.

I read all I could find about the four faults which eventually showed up:  P0050, P0155, P2254, P2247.  The thing all descriptions have in common is that a likely cause is a failed O2 sensor in that location.

I checked the wires as well as I could without removing the sensor.  Everything seems fine, though the previous tech wound the wires up a few turns when he or she twisted the sensor in.  The sensor was also quite loose when I investigated with a 22 mm wrench.

Because I had the car on the hoist with the bottom plate off, I went ahead and did an oil change.  I also erased the codes in the faint hope that tightening the sensor would do the trick, but by the time I had completed the run-in of the new oil, P0050 had popped again.

I called around for an O2 sensor.  Porsche matched NAPA’s price for a BOSCH unit at $230 CDN* plus tax or $260, and offered the OEM model at a one-time price of $250 CDN plus HST.  The catch was that the BOSCH would be available next morning.  The Porsche item might take some time.

My son picked up the BOSCH sensor in Ottawa this morning.

More to come, no doubt.

*Before readers react in horror to this price, the U.S. dollar is trading at $1.34 CDN.  Pelican parts wants $134.50 USD for this part.  That would work out to $210 CDN with exchange and HST, so it’s hardly worth the delay,  1 1/2 hours of driving, bridge toll of $3.00, and a Kinek fee of $6.00 for the online product.  The Porsche price is also a few dollars cheaper than the NAPA price listed on the NAPA Canada website.  On the other hand, a Cayenne S has four of these sensors, all different, but all expensive.

This expense marks the first time I have given any serious thought to the high cost of maintaining this car.

UPDATE:  9 December, 2018

Charlie delivered the new O2 sensor from Ottawa and helped me remove the old one and thread in the new one.  An extra set of young, experienced hands was a big help.  Before the new sensor came, after I had changed Ruby’s oil I erased the codes and drove it briefly, then raised it, running, on the hoist to check for leaks.  By the time I had the car back on the floor it had popped P0050.

This time, so far at least, there are no codes.

While changing this sensor is no picnic, we both agreed that it was considerably easier than replacing the alternator on the family Lexus.

UPDATE:  10 December, 2018

The first hour of driving produced no codes.  Fuel mileage is marginally improved, back to the level it was before the sensor began to misbehave.

UPDATE:  14 December, 2018*

The OBDII meter moved back to my truck today.  Ruby seems fine, now.

*I actually made the switch yesterday, but such is the state of my triskaidekaphobia that I falsified the date <weak grin>.

UPDATE:  2 February, 2018

Ruby has been very well-behaved since the O2 sensor replacement.  With the OEM coils the engine is marvellously elastic, though fuel mileage has taken a beating with the switch to winter gas at the local stations.  On the other hand, gas prices have dropped sharply, and as long as premium is priced at under $1.25 per litre, Ruby’s replacement with a Prius AWD recedes into the future.