I am having this code come up. I have checked for vaccum leaks, replaced the pcv elbow, cleaned the MAF, replaced the fuel filter. I can reset the code and drive 20-50 miles and the code will come back. The truck seems to run fine and isn't making bad mileage. Does anyone have any suggestions? I do not have access to a scanner. Can the o2 sensor cause this code? The truck has 204000 miles.

 

Do you have an exhaust leak on the passenger side? Try running some Techron in the gas in case you have dirty injectors. Very doubtful it's a bad O2 itself.