Originally Posted by
KhanTyranitar
Ok, that sensor will need to be replaced for sure. The converters on F series rarely fail unless the O2 sensor starts to get out of whack, even if there are no sensor codes. If you have sensor codes, then the sensor is definitely shot. The sensors output voltage drops over time, which the computer interprets as a lean condition. This causes the vehicle to run rich, which in turn damages the cats. Add a slight misfire or just incomplete combustion on one of more cylinders, that leaves unused oxygen, which then mixes with unburned fuel in the cat, causing it to overheat.
If you need to replace the sensor anyway, you can cut the wire at the base of the sensor and get a closed end wrench with six sides on that sucker. Then you can apply as much torque as you need to break that loose. Also soak it with PB Blaster a few hours ahead of time to give it your best shot. Make sure you use anti-seize with the new one. Running an appropriate sized tap to clean the threads probably isn't a bad idea, the correct size is 18mm x 1.50 pitch.
As far as the cats, go for the Eastern cats, they make a better product than anyone else at this point. Magnaflow is having major issues with their catalyst, Davico uses Magnaflow cats.
Great info.
I've hit it a couple of times already with PB blaster. I was hesitant to cut the wire on the sensor because I wasn't sure how I'd replace it all. I was trying to trace it back to see where the wire starts or plugs in. I'd guess that they probably have a plug end at some point.
Eastern cats are what I'll focus on than. Seems like they are priced a pretty good anyway.
Remaining questions.
1.) Does the exhaust have to come off (or how much of it) to get the cat off.
2.) Do I replace both Cats - Has been somewhat answered. I'm guessing I probably should AT LEAST replace the sensors on that one too. If this one has been damage from over heat prior to this, I'd guess the other side probably was exposed to the same conditions and will probably fail early also.
3.) Pipes and Muffler seems to be in good shape, But since I'm doing all this fiddling already, am I best to replace that too so to avoid it in the future.