I have a 2004 silverado 2500hd with the 6.0 gas engine with 116,000 miles. I had a p0300 code come up with a o2 sensor code so i replaced both upstream o2 sensors. code went away for awhile and come back so i replaced the plugs and wires, cleaned the throttle body and mass air flow sensor and code sill come up. then i replaced the crank sensor and the check engine would flash as soon as i hit 2000 rpms while driving. then today i replaced the cam sensor and still the check engine light flashes after 2000 rpms and throws a p0300 code after two drive cycles. also the check engine never flashed before the crank sensor was replaced. any help fixing this problem?

 

Is it still throwing the code for the o2's?

Had a similar problem with my 05 last year. Was throwing a P0300, P0101 and P0420, I think...

I replaced plugs wires, o2's and cleaned the MAF with no change. It turned out to be a clogged cat.

 

My buddy ran into the same problem with a 04 1500 spent hundreds going to the dealer and they couldn't even figure it out and finally we realized it was a bad cat!

 

it is just throwing a p0300 code after two drive cycles. check engine light flashes every time after 1800-2000 rpms. the flashing check engine light did not start untill i changed the crank sensor. i have also changed the cam sensor and still the same thing. no 02 codes.

 

i also have 116,000 miles on the truck.

 

You said it was throwing P0300 before the crank senor was replaced.

When the Check engine light starts flashing it means the miss is sever enough to damage the Catalytic converters.

What are you using to read the codes???

 

my code reader. yes it had a p0300 before the crank sensor was replaced. but did not start flashing till after i replaced the sensor. you think it might need a crank sensor relearn?

 

Its possible. How ever you really need to see the live data values to know whats going on. If there is a miss in one of the cylinders it would show in the data stream. It could be mechanical or electrical causeing the issue. Whith out more info were just throwing guesses out...

Usually when it starts flashing its an indication of a dead miss under load.

 

ok well it goes in monday for a DIAGNOSTIC test.

 

Thats gonna be your best bet if you don't have a real scan tool.