Search results

  1. C

    PO300 and brutal fuel mileage

    Thanks everyone, My next day off is on Monday so I will definitely try reading the temp before and after the cats and check the O2 sensors. I'll also see if I can borrow a reader to get some more data.
  2. C

    PO300 and brutal fuel mileage

    Thank you, that is a great place to start. I haven't put a scanner on it (I don't have one, just a code reader), but because it runs fine when cold and only idles poorly when warmed up, wouldn't it be more likely be related to a temperature sensitive item (O2 sensor or cats), rather than a...
  3. C

    PO300 and brutal fuel mileage

    I installed new NGK wires and plugs, but I haven't tried running it in the dark. Been waiting on coil packs because I don't want to spend $400 needlessly, but I might have to.
  4. C

    PO300 and brutal fuel mileage

    I've got a 2002 Yukon Denali, 6.0 Vortec. It recently started throwing a PO300 code and my fuel mileage has gone from about 14 mpg to about 9 mpg. Idles fine when cold but rough once it has warmed up. I've replaced spark plugs and spark plug wires, but that hasn't fixed anything. Wondering if...
  5. C

    Problem with front climate control

    I am having a problem with the climate control in my 2002 Yukon Denali. Regardless of where I set the temperature dial on the main climate control, it only blows hot air. good thing this is happening in February and not July! When I press the A/C button the orange light flashes three times...
  6. C

    02 Tahoe: dash & interior lights went OFF

    Funny, I am having the same problem on my 2002 Denali and was just about to post when I saw this. Sporadic lighting for instrument panel, stereo and trip computer. The sometimes they work, sometimes they don't. Radio still works even when lights off, so wasn't sure what it could be. Ordered a...

Forum statistics

Threads
129,112
Posts
1,810,606
Members
92,197
Latest member
jm6t

Latest posts

Top