Well, I had the already known to some people, P0128 CEL something about cooling system. However, shortly after it came up my exhaust started sounding deeper, as If I had a tip installed or something, mainly under 2k RPMs, and it keeps creepin up the tach to about 2k now. Also I checked the tip of my car and the bottom half seems incredibly dirty, dark, maybe running extra rich? My cel says cooling system but I had the same CEL come up before and It was coupled with another code saying it was too rich at idle. Now that code is gone. But it could still be happening? Any ideas guys, I have had a small performance/ gas mileage drop also. I want to get a few ideas before dumping out the big buxs. Thanks in advance everyone.