My son has a 1999 Cadillac that has a repeated o2 sensor failure. It is the one on the right side of the engine block up front. Not hard to get to from the bottom but a at sixty bucks a shot it can get pricey. What would cause this repeated fail and how would you fix it?

 

depends bad sensor
what code did u get this time?
what code did u get last time?
bad gas , something is clogging up the sensor
or the heating element is crap
car misfiring a too rich mix
partial block cat
many causes