hi, ive been workin on cars quite a while now mostly just jeeps but i bought a 97 jeep grand cherokee laredo in march that had a slight misfire. i assumed it was simply the plugs but recently after had to replace the valve cover and pcv valve the plugs look great the wires are great but its still gettin bad...it will idle all day long but if i hold it up to about 2000 rpms when i let off it dies or it starts bogging and dies...the computer read multiple misfire in 5 and 6, major vacuum leak, bank 1 sensor 2, and fuel pressure. but there are no vacuum leaks at all and my o2 sensors are fine...any ideas

 

Welcome to CF.
I'm assuming you have the 4.0L I6.
Check:
the ground at the FI harness;
the TPS. Just my opinion of course.
Dan

 

intake gasket? I am assuming u checked, but this will cause this.