Pre Cat Failure?

[jeoff]

Hi guys wondering if anyone has encounterd this problem.. i own a 51 mr2 roadster..the car will not really rev above 3 thousand rpm..and loses power going up hills, it felt to me like an electrical problem so i changed the plugs and then the coils but its still the same..i then found your site which mentions the pre cat failure could it be this??.. the symptoms sound familiar only thing is it hasnt lost a drop of oil or water there is no white in the oil and the engine never overheats starts first time and dosent make any funy noises at tickover.. ive yet to check the precats but does this sound right? and could anyone tell me where to get the socket to take the sensors out or will any 22ml socket do? thanks in advance tim