hey i no this isnt a ford problem but here i go. i brother has a 1998 jeep grand cherokkee and every time he starts it up it has a knocking noise to it. also hes having problems with power when hes on the highway for a couple of minutes and trys ro accelarate theirs nothing their. i appreciate all help thanks.

 

His vehicle has a broken element in the catayltic converter. Very common problem with all model jeeps. Sounds like rocks in a can during start up, or shut down.

 

thanks so much but can this also be why he has no power on the highway after he trys to accelarate.

 

If the element is turned sideways in converter and restricting exhaust exit, then yes it is probable.

 

the element is from the front and it knocks only from a cold start. he has abnormal oil pressure and a check engine light

 

i meant i dont think its the element. the knocking is from the front of the car and the car slows down while it knocks