The check engine light won't go away. Ive check distributor replaced coil, cap, rotor, spark plugs and wires are only 5 months old. Checked maf and cleaned it, it's an 03 so it has no egr. Only thing left is cat and o2 sensors I believe. Could these give me a p0300?

 

How did you check the distributor? It looks like you’ve fired the parts cannon, but have you done any diagnostics?

 

Yes I have done some diagnostics...there were originally 2 codes. One went away after I changed coil. But the P0300 is still up. Finally put in the ignition control module...idles better now, but still there

 

Happened to me. P0300. Couldn't figure it out. Finally realized that the driver's side O2 sensor was frozen at .2 volts. Didn't throw a code cause it hadn't failed. Replaced the sensor and all is well.

Voltage should move up and down on an O2 sensor.

Good luck,

dviles


Also could be a bent valve.

 

I have not looked into o2 sensors at all. When you had the code, did you have a misfire that you can feel

 

No. Occasionally when I would get on the accelerator, the light would flash and bog down a bit. But, my O2 was telling the computer to dump more fuel into the driver's side of the engine. You could smell the fuel. Also, the plugs were cruddier on that side from the extra fuel.

 

I went ahead and ordered 3 o2 sensors...might as well replace them. I know alot of people dont care for replacing parts until it gets fixed, but with the plans i have more my blazer, i would rather have a bunch of parts replaced before I start really driving it hard!!

 

So now the p0300 is gone..but the p0016 is back

 

I had the p0300 code and turned out to be the spider assembly under the upper plenum. I changed out to an updated aftermarket unit from RockAuto and it ran smooth with great acceleration, no code.

 

Did the same to me.. but, I had a spark plug wire off the plug on Cylinder #2. So, that cylinder was not getting spark.

More on the obvious side, yes, but, P0300 can also be if your intake is loose or having a vacuum leak.