Cadillac Escalade, EXT and ESV Forum - 1999 - 2006 Discussion, Fuel Pump, MAF sensor, oxygen sensor, Catalyic converter ??? in Cadillac Escalade Forums; I have a 2004 Escalade 6.0 AWD. At 100k miles I changed the spark plugs (E3), wires(ACdelco), K&N filter and ...
I have a 2004 Escalade 6.0 AWD. At 100k miles I changed the spark plugs (E3), wires(ACdelco), K&N filter and used Sea Foam in the gas tank. I first noticed problems with the idle about 300 miles after the tune-up and there was a random cylinder misfire code. I removed the E3 spark plugs and noticed that the spark plugs were not centered on the electrode and I replaced them with a set of NGK iridium and bought a Diablo Predator tuner and loaded the 87 octane tune. About a month passed and the car started to hesitate when I would accelerate from a stop and I was only able to use about 20% throttle. I used the programmer to manually check for codes and there was P0131 & P0151. I replaced both pre-cat o2 sensors since the car was at 100k miles. The next day the same problem existed and I checked for a vacuum leak using brake cleaner around the intake runners by the heads...no signs of a leak. I cleaned the MAF and replaced the fuel pump since the fuel pressure was 60 at start-up then would drop to 20psi under 60% throttle. The temp of the catalyic converters after a 15min drive was about 300 degrees.
Besides replacing the fuel pump again is there anything that i could be missing?
This may sound stupid but how about the fuel filter? Has it ever been changed? I know the older models have an in-line filter and I think somewhere I read that the newer models (03+) have a non-serviceable filter? I could be way off base though, so don't quote me.