I know the main cat is 2.25" as opposed to the regular one which is 2". Im not sure if the precats are different or not. I always thought they were the same...

I guess its possible that they are different...

1999 Mystique LS V6 Alpine CDA-9807, Rear deck sub, Opt. TB, K&N RU-3530/MAF adaptor, custom heatshield, FSVT 17's, SCT 4-program chip, Eibach's/ST200's, Hella Fogs...