About to buy my first M3, thought id ask the forum first

[pbonsalb]

What is the date code on the used tires? I would go 255/275 on stock wheels.

[ccdies79 M3]

I thought I found a pretty good deal on the one that I bought, but in the first 1 month that I bought it I replaced both rear wheel sensors, starter, fuel tank breather Valve, and now I have been getting a high trans temp alarm (DCT trans), acouple of times it throws the car in nutrel, it only stays In for a coupls of seconds, even while I’m parked in a parking spot at work it’ll go off, so I guess it really dont matter what you find, you might be buying some ones else’s headache,

[khanxyz0z]

So im about to buy 18 inch arc-8 wheels depending on adive il select rim width, what im trying to figure out for a few days is, should i go with a 40 tire and stick with 255/40/18 and 275/40/18 the max before it rubs for the front, since the roads here are pretty bad. A couple people suggested go 265/35/18 and 295/35/18 since its a wider tire and has a bit better grip. Just want to ask is their really that much more grip, what would you guys suggest, would a 40 tire give that much more comfort compared to 35 or would a slighly wider tire give better grip.
Michellin PSS for spring next month.

Thanks

[Deen HK]

How wide of a wheel are you getting, you might need to camber the front just a little to prevent rubbing. A 40 sidewall isn't too beefy and definitely offers some more cushion. Personally i'd go with the 265/35/18 and 295/35/18 setup though.

[khanxyz0z]

So i put on back my resonators and secondary cats on and the check engine is on after about 70 miles after.
I know the car had a tune since it was straight piped and no check engine light was on before.
Isnt it weird after adding stuff back on that light would turn on.
Would i need to get it tubed again to remove check engine light.(sucks that i dont know which company tuned it before i bought it)

[CamasM3e93]

Originally Posted by khanxyz0z

So i put on back my resonators and secondary cats on and the check engine is on after about 70 miles after.
I know the car had a tune since it was straight piped and no check engine light was on before.
Isnt it weird after adding stuff back on that light would turn on.
Would i need to get it tubed again to remove check engine light.(sucks that i dont know which company tuned it before i bought it)

Straight piped setups use stage 2 tunes.
If you have a tune for a straight pipe setup and you add restriction with the secondary cats without updating the tune, it will alter the air-fuel ratio and you will run rich. If it’s more than the car can adjust for, it will throw a CEL. I would seek out a stage 1 tune if an obd2 scan points you in that direction. I had similar on another car/platform recently and it was an error code from both upstream oxygen sensors which tells you it’s a systemic thing rather than a sensor failure on one side.