I have a wide range of codes that appear intermittently.....

Hi there, Sorry to hear about all your car troubles. My Name is \*\*\*\*\* \*\*\*\*\* I am an ASE Master Tech here to assist you with your vehicle. Please understand I am not there with you, But I am here to help. Any information about what is going on is greatly appreciated. The system will ask for a phone call, Please let me know if you want this option as I am not always available to do so. What are the other codes that are coming up?

P0351 - [Ignition Coil](/topics-ignition-coil-chevy/) A Primary/Secondary Circuit C342D - Manuf. Control P0055 - H02S Heater Resistance Bank 1 Sensor 3 C3064- Manuf. Control (only occasionally, not as frequent) P0420 - Cat System Efficiency Below Threshold Bank 1 (missing cat, figured) P0300 - Random / Multiple Cylinder Misfire DetectedFor additional info. I had a pinhole leak in the intake manifold, which ran the truck lean for over 6 months. I patched the fix, but believe this to be the reason the cat blew out.

If you clear these faults. What comes back after a quick drive?

P0420 only. Then they will all return at once accompanied by the random misfiring.

We will need to know what cylinders are actually misfiring to move forward since these codes are all over the place. Do you feel the [engine](/topics-engine-chevy/) misfires?

the whole truck shakes pretty badly. Is there anything I can do to try to find that out?

I will typically use my scan tool to watch for this data live. But a basic test that will work is to disconnect 1 ignition coil at a time while it is misfiring. If there is no difference in engine noise then this is a faulty cylinder. The only thing here is that you are getting a p0300 which means to me that all cylinders are acting up. So we need to find something all cylinders have in common. Since you only have 1 missing cat it will not be that. But since you have an intake manifold leak and this feeds all cylinders I would suggest starting here. Especially since it has been an issue before and could be causing our issue now. I like to use the K.I.S.S. Method of thinking. Or Keep it simple stupid. Lets not chase something we cannot find when we know a fault is right in front of us. So my recommendation is to replace the faulty manifold and retry testing to see what faults are coming back. Do a Hard reset after this repair. This is where you disconnect the battery for 30 minutes or more. You can also do this while doing the repair. Make sure to reconnect everything before connecting the battery. This will clear all faults in all systems and give you a better idea of what to look for. I always shoot for a 5 start review. If you have any other questions or in need of any other help, please let me know. If you think my answer was not that of a 5 star rating please let me know what I can do to assist you further. I want to answer all concerns that you have about this issue. Tips are not required but highly suggested, I work hard to give you the best answer and appreciate the extra thank you on your side. Thank you for understanding and thank you for using Just Answer!

Not sure if this is still open... but I just had some new codes thrown. P0351, P0353, P0355, P0357. It looks like the drivers side is all having faulty coil signals. Perhaps its an electrical issue then?

Yes most likely. You will want to check this fuse and the ground that each of these coils share. If you need any more assistance please just accept the offer for additional help and we can get to the bottom of these codes. I can get some wiring diagrams and troubleshooting guides for these codes.