I first installed a AEM cold air intake on my '03 mazda 6 3.0. It gave me a noticeable hp increase and no negative issues. Next came the Magnaflow performance cat back exhaust. At first all was well, but as time has gone by I have experienced and increasing negative power issue. Essentially, I step on the gas and I get a run away rpm increase with no initial power increase until I hit the upper rpm's. Almost like the car is being rev'd in neutral. Is there an adjustment or upgrade to the computer/airflow sensor to correct this issue??? I hope so as I would hate to have to put the stock exhaust back on. Also this past year I've noticed abnormally high oil consumption with no leaks or evidence of it coming out the exhaust.

VTodd

 

Take the throttle body off & clean it. See if this helps with the RPM issue. Especially if the stamping on the T/Body is AA. These are a known common issue with the earlier V6 models. With the oil consumption, that can usually be traced to a bad PCV valve. Have you changed yours since purchasing the car? Again, another quirk of the earlier V6 models. Ask if you have any more questions.

-Sheldon.