I had one catalytic converter replaced in AUG 2014, would there be any need to replace both in April 2016?
Have you driven over anything you shouldn't have that could have possibly damaged them? Have you checked the plugs on the side? I know these are impressively fun cars to drive. However I do not know the capacity in which you drive. It's just when I think of this car, I think of terrain driving, not highway. So that's my initial response. What was the issue with your first cat you replaced?
No major off road driving. in 2014 tried replacing the O2 sensors because of the check engine light which continued to come off and on, replaced one converter. Check engine light has continued to be off and on, more on recently. Warning light came up with cat converter per the dealer. I have 112,000 miles on the car.
If you live in California, maybe YES and here's why?? I had a 1985 Ford Thunderbird several years ago. I had three cats on the car and it failed the emissions test. My mechanic at the time pointed out that if you only replace one, it puts more stress on the remaining units and makes the good one fail more quickly. They're all supposed to work in harmony, so, yes, I think replacing them at the same time is a good idea. My car passed the next emissions test with extremely impressive scores. Good luck.
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