2004 chevy tahoe problem with code 300-misfire

[dalodarryl]

i got a problem with my tahoe 5.3L 4wd, engine lite came on and it read 300-misfire, i change all plugs and oil and filter, code came back and still getting gas into oil, can it be my o2 sensors, can i disconnect them all for now tell i get new ones in, would this stop it from getting gas in the oil, plus when at idol the oil pressure is good, but when starting to drive it goes down to zero pressure, speedometer is stuck too.

 

[Sepiroth]

It seems to me that you could have a bad injector or a fuel related issue, not O2, at least not yet.

 

[dalodarryl]

how do u narrow it down to find the bad injector?

 

[BLACK_DENALI]

i got a problem with my tahoe 5.3L 4wd, engine lite came on and it read 300-misfire, i change all plugs and oil and filter, code came back and still getting gas into oil, can it be my o2 sensors, can i disconnect them all for now tell i get new ones in, would this stop it from getting gas in the oil, plus when at idol the oil pressure is good, but when starting to drive it goes down to zero pressure, speedometer is stuck too.

A bad fuel pressure regulator on the vacuum side can suck raw fuel into the cylinders. I would check that first before you go crazy and start unplugging stuff at random. Do you remember if the plugs were wet with gas, especially on the passenger’s side?

 

[dalodarryl]

all plugs were black and dry, plus i have no oil pressure , when i start too drive, speedometer is stuck, gas still getting into oil. i change the plugs @50000k before , then know at 70000k. ???????????????

 

['98customhoe]

my 1998 Tahoe is reading a misfire but my problem is a almost dead. My 7th cylinder isn't working at full capacity. Maybe you've got the exact same problem