Hello esteemed and learned members! I am throwing my problem out here seeking advice. My 03' MCS threw a TC PO340 out of the blue. I just got the car back from the shop after having the Crankshaft Sensor replaced. The car had ran fantastic after my son had installed a low mileage short block, and a bunch of "go fast" mods in my non-runner auction project. But periodically I would get a miss and even a stall or no start PO301 code. The new Crank Sensor supposedly corrected the problem. Now this 600 mis or so later. The upgrades that went on with the 30k donor include; HD flywheel,clutch,Crank Super Pulley, 15% SC pulley, cooler plugs, MSD coil, Magnecor racing wires, Alta cat back, SSI intake. Timing chain belts all the due dillegence stuff I could think of as well. I'm at the end of my rope...the car is a blast to drive, but we have "trust" issues. I'm wondering if the Camshaft Sensor is the problem, or is there issues with the communication between the two sensors? Could the ECU be confused by the performance upgrades?

Thanks in advance for your ideas...!

 

Very common upgrades. Wouldn't worry about confusing the ECU. Others have complained about MSD coil not playing well, so I would go back to stock coil if you can. I don't have one myself.

Camshaft sensors do go bad. But, maybe check the electrical connection first? Perhaps with the recent work it was left loose.

 

Did you figure this one out? Did you end up replacing the camshaft position sensor?

I just swapped mine out after he threw that code and all appears to be well now.

 

I'm grateful for the respondents to my humble plight...that said, I think replacing the camshaft pos sensor did resolve the issue. I'm still wary, but so far so good! I replaced two motor mounts at the same time. They were bad and I couldn't help but wonder if the rocking about might have been an issue...