Maintenance: Changing Spark Plug wires and o2 sensor

Have you guys ever changed your spark plug wires and o2 sensors even though theres nothing wrong with them? Mine have 229k miles on them and have never been changed. I've been on the fence about doing it or not since I'm not sure if i'll be replacing parts just for the hell of it. Cant really find any concrete information online so I'm looking for your experience. Anything else i should look into changing while I'm at it? I've done normal stuff like air filters and spark plugs but not really much else. its probably been a few years since i've had a transmission flush done (been reading its not always the best thing to do).

It's called preventative maintenance I would also do coil packs

+1 on the coil packs,.... Don't wait for them to cause problems.

O2 sensors can fail completely but will throw a code if the do. With age, O2 sensors begin to "slow down" or "fade" until they eventually throw a code.
I personally don't think it's worth the money to change them,... I'm waiting for my ECU to tell me when to do it. Can't hurt though and your car may run a bit better.

What I remember about flushing the ATF is that if your car had NEVER been flushed before then don't do it. It's even to the point where you should save the old ATF and put it back in if you ever have to work on your tranny.

Apparently our Auto tranny adjusts itself over time to the fluid and new fluid screws things up bad. Some guys would change out a few liters at a time to give it time to readjust.

Kind of a tough call in your case because it has been done before.

Here's the big list of things to consider checking.

(checking the water level in your battery is something that people tend to forget (unless it's maintenance free))

Here's a link to my How-To for a Fuel Filter change: (yes,... our car has one)

http://www.mazdas247.com/forum/show...How-To-Change-Your-Fuel-Filter-(lots-of-pics)

Thanks for the replies. So Far I have the following things im going to do.

-Spark Plug Wires
-Ignition Coils
-O2 Sensor
-Transmission Flush
-Coolant Flush (this is something i've had pending for a while i just havent done it since i dont know where to recycle the coolant)
-Fuel Filter

We don't have a fuel filter...

It's not just a fuel pump housing,... there's a built-in fuel filter. Mine was pretty full of crap after 12 years.

There's the "strainer" or "sock" (low pressure) and the one people don't know about (even some Mazda mechanics).

NestorGonzalez said:

... So Far I have the following things im going to do.

...-Fuel Filter

Click to expand...

You live in Cali,... you should be able to do this job in half an hour,... (you shouldn't have the rot I did)

A new one is $27 from Rock Auto, they call it a "fuel pump filter",... Way more money from Mazda.