JesLet

iTrader: (19)

My SC300 has 186k miles and had no idea when was the last time it was replaced.

I'd Like to know when we are supposed to change them as a part of preventative maintenance.

I don't want my CEL light to show up on my dash, plus I am rigorously tuning up my car as a daily driver. About 55 miles a day, 5-6 days per week. I'd like to see my car at 300k.

Should I take one off and inspect it? If so, what should I look for? Should get rid of them if I found white/gray/black carbon build up? Am I able to clean it?

Ali SC3

iTrader: (10)

whats ur gas mileage like? 100k interval is suggested for a stock type car.
there is no way to look at them and know for sure (unless its horribly disfigured), you would need to have an oscilloscope.
If you are gonna go through the trouble of removing them just replace them. you can get some good deals online.

fried_rice

iTrader: (20)

I wouldn't worry about them unless the car throws a code. The ecu is is pretty good even without the sensors, if you're throwing a code it will cause the ecu to go into limp mode, which would need replacing.

JesLet

iTrader: (19)

Thanks for the reply.

My car gets 25-28 on the freeway which is good right? Can you tell me where are the good deals online?

Ali SC3

iTrader: (10)

thats pretty good mileage for a 400 so they are probably getting the job done still.
you need to check how many wires are on your 02 sensor, and once you figure that out (look it up online or visual inspection), you can order an oem replacement (expensive) or order a universal bosch sensor (or whatever brand you like) with the right number of wires and connect it yourself (much cheaper).

JesLet

iTrader: (19)

Hey, I have a 300 now.

Ali SC3

iTrader: (10)

lol I read the first car in the sig, then i moved on.. its still good mpg either way.