lisa Williams

My 05 GMC SIERRA has recently started running crappy. One it hits like 55mph it's ok. Had guy change my calve cover gaskets cause they'd been leaking for awhile. Mind u it ran fine til then. Grommets were not replaced. Drove bout 20 miles and check in goes to flashing and it starts misfiring and runs ragged til u hit bout 50 or 55. Checked codes it's a po300 code. So he suggested new spark plugs. Then it threw code for misfire on 4 so we changed that wire to plug plus put an 02 sensor. Back to code PO300 and it runs just as crappy as b4. We'll this mechanic says he feels full injector needs to be changed to #6 cause he took wires off and zero happened at number 6. So changed it. Still no better. I'm a woman and I don't have it to keep buying and it's still no better. Any suggestions on what I can do to figure it out? I'm bout ready to just be done with it. Crazy thing is....it ran perfect til valve cover gaskets replaced. Any suggestions....I'm desperate

I have 05 GMC SIERRA 5.3 V8 4 wheel drive truck. Great truck. Had a little oil leak so decided to get valve cover gaskets replaced when I got my oil and filter done. Since then it sputters/hesitates and throws PO300 CODE. Changed 02 sensor and plugs. Still doing it and throwing the code. I don't have money to keep buying to not fix. It ran brand new til had valve cover gaskets done

05 GMC Sierra 1500 throws code C0055 for rear sensor or something like that which I've changed 4xs plus a new ECM. The issue is: abs..brake light..check engine light will all come on...speed odometer goes nuts...and transmission won't shift. Thing is....it doesn't do it all the time. It goes months and don't do it...then it can do it every day for a week. Trip it off with our computer thing or sometime we have to take battery cable off. Replaced the rear speed sensor...both front tire sensors...new ECM..some other things....but still does it. Can anyone please help! My email is [email protected] if u want to respond directly. Ty