just checking, I still have the occasional running problem with my cruiser, have had the truck for 50,000, what's the dealers recommended interval to change the o2 sensor, mine looks old and crusty, I was reading online that many car makers have it as a maintanance item and replace them every 50, 60, or 90k, I didn't know that this was the case. Mine has got the two inline cats on my 95 1fz