I'm an owner of a Subaru Impreza 2.0 RS MT and I would like to ask your advice about the modifications I'm planning to do.
I have read forum posts saying it's not advisable because they are oiled, which will be† bad for the MAF, particularly in Subaru vehicles. Some forumers say this will eventually make the "Check engine" signal light up on my dashboard. Is this true?
I'm also planning to install Speedlab headers on my car. And I'm thinking about the Unichip.
With these plans, how my car benefit in terms of power? How will it affect fuel consumption? Will the car make more noise? And would you advise me to go for these mods?
Thank you sir and more power!
For the sake of full disclosure, and in case you don't know yet, I'm a part of Speedlab. That being said, my answer to your question will be the same if I were with a different company.
The issue about oil-bath-type air filters like K&N causing MAF failures have been around for quite some time and will probably keep popping up every so often. The issue can best be answered by this link found on K&N's website.
The short version though is you've don't have much to worry about when it comes to K&N. I've been using it for close to 20 years and will continue doing so until something better comes along. I won't hold my breathe waiting for that time to come though.
SpeedLab is perhaps the only local shop that develops, dyno tests and markets a comprehensive line of affordable aftermarket goodies that truly work for the local car enthusiast; and publish results online. I can't think of any other local tuning shop that does the same. That alone speaks tons and sets it apart from the rest of the local tuning shops.
A drop in K&N filter won't increase induction noise. An open-type filter, be it K&N or some other brand, will. This is so because you’re removing the air box that muffles the noise. It's not annoying to most people.
The headers will increase noise because of the difference in the material used when compared to the factory header. If it's a concern perhaps you can listen to someone who's had the mod done to theirs before you decide if it's for you or not.
A Unichip doesn't directly increase noise and is used for optimizing the tuning of the vehicles they are installed on.
Fuel consumption will always depend on how you drive and when a vehicle is optimized for efficiency, it will usually result in better fuel economy if the driver is capable of driving it in a manner that takes advantage of such.
Modifications are a personal choice as only you can decide for yourself if the money you paid is worth the satisfaction you get.