Valve lifter ticking

[98mazdaman]

Hello. My 98 3.0 sounds like the valve lifters are ticking while accelerating in 4th or 5th gear. The lifters don't seem to make any noise in lower gears. I was wondering if this is a big problem, and if so, how easy/expensive of a fix it is. Thanks!

 

[MrE_Powers]

check for exhaust leak and you may also have your cps starting to go out.