Need ideas Lack of power/ poor idle /exhaust sound 2.7

Ok I'll try 2 B quick here ! I have a 99 Taco 158K 2.7 I have 25K on new wires an plugs. A couple months ago it started 2 hesitate during acceleration/shifting. I have done the following cleaned throttle body, TBsenor checked @ Autozone, Inspected & didn't find any vaccume leaks, new fule filter,new air filter, injector cleaner (2 tanks) It Ran alot better but only a couple of weeks and it came back ! Not only that but now it has a rough idle and will die at stops ! So I Found TW.com since then I have cleaned the MAF sensor, connections, new battery terms., since all these attemps it still lacks power in 5th ( Cant do more than 70-75 on hwy) and it still idles bad. Now its making a cherping sound when it starts for only a few seconds then its a sssst.....ssssst .....ssssst sound from the exhaust manifold kinda sounds like a lifter knock ??? I have read a few post about cracking manifolds is this common for 1st Gen taco's ? Any ideas what I can check next ?

 

Sorry I re-read your post and noticed you did change the fuel filter. My bad.

 

Did you change the PCV valve? Are you using more oil or coolent than normal? Clogged cat? O2 sensors? Things to check as well. Also try seafoam treatment that usually helps out a bit.

 

No worrie's Barry ! Josh, No not the PCV valve good point ! No on both for the oil & coolent just normal ! I Broke down an made an Appt. to have a full Diagnostic tomorrow morning ! These guys are good but a lil spendy ! I just hate pay $50- $100 bucks on someone to just tell me whats wrong with it ! I'll keep you all updated when I find out ! Thanks !

 

Well I had my tech look at it and he said he didn't have a lot of time to look at it in detail so he asked me 2 bring it back ! He did confirm that my exhaust mainfold was cracked and that something was wrong with the idle. he wanted me to come back for a compression test on friday ! I explained my sittuation with hunts and the timing i was up against ! Even if he did get all the right answers an found a major issue an could have got it fixed i will never know ! Sorry guy's But I got frustraighted and traded it in and bought an 04 Superduty ! It was only a matter of time anyway ! I haul to many toy's a boat, wheelers, & a trailer. Sorry Guys ! I really would like to have kept the truck for running but, I just got tired of working pon it !