I was hoping for some input from people with higher mileage 6's. Mine is currently approaching 160k while it doesn't seem to have any issues is there anything I should start to worry about? The only thing I haven't done is eliminate the pre cats because I'm afraid of breaking off the rusty studs in the head. And I suspect my A/C compressor might be starting to fail. I have deleted the egr tube. The car is a 2007 3.0 V6 with the 6sp auto Aisin trans.

Things I have already done/do:

Spark plugs/ coils

Flushed ALL of the fluids ATF, PS fluid, Coolant, even the brake fluid

Regular oil changes with full synthetic high mileage oil with Hy-Per lube

water pump

cam seal

front crank seal

serp belt

idler pulley


Thanks for any input.

At 200k, my radiator split and the rear cat on the rear header gave out. Also typical suspension replacements as tie rods and control arms. My engine and trans were still going strong at 245k when it was recently rear ended and totalled.

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I work in a pretty big Mazda dealership. The most frequent problems we see with higher mileage 1st gen cars are lower control arms and catalytic converters. By and large, it they have been maintained well, the engines are good for well over 200,000 miles.

My car has 270,000KM (about 167,000 miles) and it still runs so strong and gets awesome gas mileage. My only real issue is rust. I'm replacing my rear quarters this winter and I plan on driving my car till it cannot be driven.


Just keep maintaining it, they do run a very long time when taken care of.

So far it seems like I definitely need to gut my pre cats. I have already had control arm issues on the driver side I have the ones for the passenger side I just haven’t done them yet. @b1lk1 I too am battling rust on my rear quarters and the bottoms of my doors. As far as maintenance I service everything on or usually before it’s recomended interval. I’m no stranger to high mileage vehicles they just all seem to have odd things happen to them, we had a 98 ram 1500 sport that needed rod bearings at 215k a suburban that had to have a fuel pump and an alternator at 220k and then I had an Audi A4 that needed a turbo at 185k.

Gutting the precats is a guaranteed check engine light. I'm hoping that after I replace the converters in the CPE y-pipe that I can get my light off long enough for an emissions test. Only real way to keep the light off is new precats.



I bet there are TONS of good 6's in many scrapyards that simply need new converters.

I know this well


I did all my front control arms, inner and outer tie rod ends and motor mounts for a massive improvement.
I say take care of things as they arise and keep on your preventative maintenance.


The only other things that occurs to me would be the timing cover seal. Mine leaks and other frequently have this issue as well. I recently used Lucas oil stop leak (1/2 recommended amt) and it worked great on the cover seal.

I have also had to replace all the idler/tension bearings and I think the bearing on the AC clutch is going wince it whinnies nearly every cold start for about 1 second.

A CEL is not a big deal for me (while it will be annoying to look at) I do not have emissions testing where I live. I have looked at headers but the only ones I can find have been ridiculously priced.

@b1lk1 I just noticed in your sig it said 3.7 tb. I haven't seen anything on this mod yet is it worth doing, and if so what all needs to be done to do it?

The CEL will be on because deleting your precats will mess up the A/F ratio. You'll be running rich losing power and wasting fuel. The CEL for this situation is more than just a eye-sore orange light on your dash. My suggestion would be to replace the cats with a straight pipe at a muffler shop (the big open cavity of a gutted pre-cat will cause unwanted turbulence) and then get an ECU tune which will increase performance and remove the CEL. Or, like @b1lk1 suggested, go to a junkyard and pull some off another first gen. Clogged/faulty cats are often the result of a car either running overly rich or burning excessive amounts of oil. If you are consuming too much oil, switch to a thicker weight or something higher quality that won't burn as much. Be sure to check the car for codes in case you have a faulty injector or something causing the engine to run too rich.

Lower control arm failures are the result of two things. 1: Aggressive cornering, and 2: Rough, bumpy roads. It's not actually the control arm that fails (Unless your arm has physically snapped in half.) It is typically the ball-joint which becomes worn and starts to cause play. As cars became newer, manufacturers started to look for ways to cut costs with their parts so control arms and ball-joints are now integrated into one. You can check if your ball-joints are worn by lifting the car up in the car and taking a crow-bar to the arms. If the ball-joint is allowing your control arm to wiggle around, even just a little bit, you need new control arms. Replacing then will noticeably firm up your suspension and make the car drive better.