I've only had my 8 for about a month so I'm not totally sure if I have the right diagnosis. About 2 weeks ago I noticed my gas mileage went from about 15-16 to 12-13, then last night when I started her up to leave work my rpms were runnin about 2k in stead of the normal about 950ish. Once I left it warm up to go home my rpms were still high about 1050 and I had a pretty severe power loss. My question is this , is this more than likely my coils? I am just over 40k miles, 40600, and would have to assume as I bought it used that the coils have never been replaced. Any help would be greatly appreciated.

 

check MAF sensor, clean it

 

coils and spark plugs. Change them both.
Also, check your CAT after a hard drive to see if it's glowing. Could be clogged

 

thanks a ton you guys are awsome

 

so I have my coils on the way thanks for the info on that guys. I did notice after I got home from work that my cat was glowing a bit, so I will have to replace that too looks like. If I just gut that until I can get another cat will it cause any issues or damage to my engine?

 

Cat has an 80,000 mile federally mandated warranty. Go to a dealer with it as-is and get it checked out. If you gut it the warranty is gone.

Ken