Hi i have a 2000 GMC Sierra 2500 with a 6.0L V8 for the last couple weeks i have been noticing that when i turn it on the rpm are acting erratically some times when i turn it on the rpms will sit and stay closer to 1000 on my rpm gauge and if i give it a little gas it will drop down to 500 witch is were it usually is at when in park idling. That usually happens when it is kind cold out. Right now its worm out and when i turn it on the rpms go a little bit above 500 and then go down below 500 and i can feel it when it does it the truck shakes a little. I had this problem about 13 months ago and i took it in and they replaced a o2 sensor and cleaned the injectors and then it ran better for about 2 weeks then started doing it again so i took it back and they said that there was a code missing in the comp. so they fixed it. I ended up just recently replacing the o2 sensor they installed because it went bad and they wouldn't fixit because it was 1 day past the 12month warranty that gm offers . I ended up put 3 new ones in my self i have one more to go and i put new spark plugs and boots on. The o2 sensors that i put on and the spark plug boots are both bosh.
Please help me figure out the problem
Please help me figure out the problem