I kinda searched but didn't get any straight answers can anyone who actually has a 08 mr with a catback and a drop in k&n tell me whether I should get a tune on not

 

No help!

 

there is no need for a remap unless you want more power

 

Iam looking for the safety of keeping my engine from leaning out

 

From a cost / safety perspective, its better to start tuning / logging your car before adding "parts".

Drop-in K&N is no issue... A cat-back will lean out AFRs, I've heard the 08's are pig rich to being with so it may actually bring you into proper AFR range, but wouldn't knowing be better than guessing.

If you bought your car used it may have already been tuned w/stock exhaust in that case your CBE will definitely cause lean AFR's

Without a tune your cat-back will make lots of noise, but not gain as much power as tuning a stock exhaust.

 

If your is other wise stock then you should be fine as 08 have an Uber rich stock tune. However a $200 AEM wideband will tell you exactaly what A/F you are running if you want to be safe, and it is required anyway if you want to do a tune in the future.

IMO spend the $200 on a wideband, you wont regret it.

(you will regret it if you are lean and blow your motor

 

Yeah Iam not sure whether the previous owner tuned I was thinking about the Cobb ap just to be safe

 

If you're not sure what the previous owner did, you should datalog before adding *any* parts.

If you are indeed on an OE map, then a K&N and CBE will not require retuning, however as mentioned, to make use of the parts to their fullest, you'll want to tune.

 

Thanks I think my best option is to get the Cobb ap first then get my parts

 

the first tune you get (from the stock ecu tune) will be the best money you ever spend on the car
everything else after that is diminishing returns

but yes you can safely add a catback and a drop in filter with no worries at all.
you will get a better increase in performance and economy with a tune on a completely stock car, that by bolting on a full exhaust, intake, intercooler and pipes etc ec.

get the parts you want, put them on, and get it tuned!

 

there are LOTS of topics based on this....
your car from the factory makes.. 291ish... at the wheels however it is lower.. about 15-17% the factory gives a SAFE modest tune to make the car fun, yet manageable to comply with standards for the EPA and such...

tuning your car will get you anywhere from 300 hp - 330 hp at the wheels... STOCK...

bolt ons... only go further..
injectors, exhaust, downpipe, intake.. intercooler.. these will only add to that with a tune

UPPER AND LOWER intercooler pipes may not give your horsepower... BUT they dont expand and dont risk the chance of leaking or uneven boost ..

do some more searching... and reading about tuning... it took me 30 seconds to look up " Stock tune for evo x " on google...

and to be straight with the answer.. YES you should get a tune... it will be great...

 

+1 on getting a AEM Wideband