2008 S60 O2 Sensor

[beewithattitude]

I've had to replace my "back" O2 sensor . The dealership said a rodent had chewed the wires. They gave me the old sensor as proof of a rodent chewing the wires. The dealership replaced the sensor, however, a mile away from the dealership the check engine light came on again. I returned to the dealership and they noted it may have been a bad part and they would order another. Returned to the dealership for the new sensor and upon picking it up they said they couldn't get the check engine light off. They noted the rodent may have chewed more wiring and they needed more time to diagnose. Upon further diagnosis they said the "new" problem was that I need a new motor control module, but that since it seemed to be driving ok, they would drive it until I had additional problems (the repair cost was over $1800). The car drives well and still gets 420+ miles to tank.

A few days later, we noticed something hanging under the car (wires/twigs?) but couldn't get under enough to see exactly what it was. Upon having an alignment performed a day later, Firestone brought up that the O2 sensor wires were hanging under the car and were torn/shredded (they took a picture and showed it to us). They noted the wires should have been secured in some way and that somehow they were being caught and or dragged and were being severed. We looked at the old part again and it, in fact, does not look like an animal gnawing it in half but its looks mangled/severed.
Our questions-
Are there clips or mechanisms that hold the extra "pigtail" wires for the sensor? I'm thinking the original clips may have deteriorated and therefore the wiring has to be modified or the clips replaced to keep it from getting mangled and destroyed somehow. I would think the dealership should know this and I'm not happy about their "service".

How do I make sure they fix it correctly?

Besides the original diagnosis and part cost ($400+) the dealership has not charged us for subsequent diagnosis/labor. They note that "IF" they installed the part incorrectly they will fix it at no additional charge. However, when we return tomorrow to have them look at it again it will be the 6th time.

After this, I will never return to them for anything because it seems obvious they are incompetent. Am I wrong here?

[RickHaleParker]

Back in the 70s one of the top mechanics did a study across the United States. He would take a car to a shop and see what happens.

What he found is that there was a 50/50 chance one would get ripped off due to incompetence or fraud. The advice is find a competence and honest shop, then there after support that shop by taking all* your work to that shop. Natural it good for you but also one should support that which should survive the competition. If they don't survive, what is left ...

* By all I mean even the highly profitable things like oil changes instead of taking it to a Quick Lube which only does the high profit stuff and leaves you hanging on the other stuff. Struts, shocks, tires, tune ups ... ect.

[jimmy57]

If this is a case of the same rodents coming back to the scene of the crime to eat the same tasty wires it would not be the first time. Probably the 33 millionth time. Honda had several lawsuits and even a threatened (maybe it was filed) class action suit. They had several models that were attractive due to some purposely biodegradable "green" wire insulation. They csme out with rodent repelllent tape with mice with X over their body that was used to wrap some wires. If you want to know for sure get a second opinion as to the cause of those wires hanging down.
Denver built their new airport out in the prairie. Rental car agencies and regular biz travelers parking cars there were getting repetitive damage to low hanging wires. Rabbits were eating wiring they could reach like ABS wheel speed sensor leads. A friend at a Denver area dealer told me his store was taking customers and showing them the repaired wiring on car up on lift and taking before repair pictures as they had been accused many times of not actually repairing the damage when it would recur the next week.

[beewithattitude]

FYI- More information
Thank you for the feedback!
The wires are not nibbled on. It looks gnarled (like twisted/torn) but not gnawed. The black sheath is severed/split/torn in two places. Still intact otherwise with no teeth marks or other signs of damage.

Could they be getting hung up on the axle? Rubbing on the axle?
Do the after market ones come with more or longer wires? I have read in another discussion per O2 sensors to secure the "pigtail" with a zip tie.

Any information is greatly appreciated

[jimmy57]

A volvo dealer shouldn't be using aftermarket sensor and the Volvo genuine part should be identical to the one removed.