P0301 Chevrolet -

Question

i have a 2008 chevy avalanche ls with 5.3 L v8. i had beep sound come on and stability track and traction light flashing and running really rough. took it to mech and they read misfire cyl 1 they changed plug & ignition coil and was getting low compression. they than proceeded and removed and replaced lifter deactivation manifold also intake manifiold gaskets and than changed oil. still not running right. they than proceed to replace the ecm after that they determined possibly soloid stuck so they removed and repalced head gasket set and active lifter injector guide? removed and replaced head gasket set and 2 lifters. finally its running fine. 2300.00 later gave me 500 off so total 1800. drove aprox 20 miles. and same thing starts to occur. i then fed up with previous mech was referd to another. they pull same code misfire in cyl 1. they keep truck for a week and determine that the 2 lifters were installed wrong. so they replace lifters, redo oil change, have to replace manifold gaskets as they say once there removed cannot reuse? once all said in done they say that the oil pressure gauge not working? so they look into it and replace the oil sensor gauge? everything seams to be running fine. total charge 1300.00. 3 days later aprox 200 miles smae thing occurs so i call smae mech this time and take it back in they get reading that misfire cyl 1. they are really confussed as to what could be problem and want me to bring back in tomorrow so they can taker it apart again? any suggestions and or help would be greatly appreciated

Answer 1

Getting low compression? Is there any ticking noise? what happens is that there is a AFM (active fuel management)  lifter that tends to unlock or collapse or gets stuck and if this happens the result is low compression. and you will have a misfire on that cylinder, If the oil gauge is not working it needs to be check for  low oil pressure , which is the common cause for AFM lifer damage.Have the oil pressure checked. it should be at least 25psi or better.