All of these suggestions are good but i had the same issue as this guy and it was a clogged CAT. Bill and i put on the headers and de-CAT'ED it and all the power was back and no more snail performance. If it just started i can tell you that it will get worse and you will end up with no acceleration. Best way to solve this issue for good is to get rid of the CAT all together and have the code tuned out. Or buy a set of Speed Daddy Headers and put those on along with the race pipe. I'm willing to bet that your CAT is clogged. Tell me if I'm wrong but you are also experiencing a huge loss in power in every gear and it may even feel like a transmission issue but its no (just feels like one). As for diagnostics about this issue, you will not be throwing any SES lights as there is no SES code for a clogged CAT (you can debate what it is all day long but in the end if it's an electrical or sensor related issue you would be throwing a code).
