Help!!!!!!

[pacman69]

my 2005 ex cab 4.8 v8 is driving me nuts,she has 219,000 miles,no oil use...but seems like every year when it gets hot it runs slugish an usualy starts settitng off knock senser code,but now no codes an as long as you dont give moore than 1/4 throttle she runs ok....but if you need to get out in trafic an gass her its bogg city till you start backing off the gas,wouldnt even spinn in the gravel! no codes an no one seems to know whats going on!!!! even a gm dealership is stumped! usaly when this happins it stops after a lil driving....but so far been a week an still the same.really dont wanna trade it an have a payment again,but im at wits end.......replace both knock sensore last summer an the under intake wiring harness for them.

[clinebarger]

Now that the symptoms are more regular, Any Technician worth his salt will be able to diagnose it.

[pacman69]

everytime it gets hookd up....nothing shows up an everything is in spec

[truckdude239]

Then they aren't hooking it up right or don't know what to look for a tech 2 will show misfires/ fuel trims and what not. Could be a bad map sensor or bad coolant temp sensor telling computer the wrong engine temp

[clinebarger]

The problem is, The younger generation of auto techs think a scanner will tell them everything, Or worse...It will throw a code for any problem. It's NOT true.

Was fuel pressure monitored while it's acting up?
Was the MAF sensor data logged?

[pacman69]

have no idea...but will check into it and see.

[truckdude239]

Originally Posted by clinebarger

The problem is, The younger generation of auto techs think a scanner will tell them everything, Or worse...It will throw a code for any problem. It's NOT true.

Was fuel pressure monitored while it's acting up?
Was the MAF sensor data logged?

i totally agree. i totally hate diag work,