07 corolla P0351 intermittent not cop or ecm?

Hi so no easy or quick fix time to get it to a toyota dealer.

Oh

P0351 - Ignition Coil 1 Control Circuit

Maybe a bad coil. Swap them around to see if the code changes from 1st coil, to 2nd coil, to 3rd coil, then through process of elimination, replace the bad coil or leads to the coil.

P0351, coil A (number 1 coil, coil on the number 1 cylinder) has a circuit malfunction. Replace the number 1 coil (if the coil has not been replaced) and replace all the plugs while you are at it. Clear the codes with a scan tool (get it cleared with a cheap scan tool you can get a car parts store). No joy, see a very good diagnosis expert mechanic.

Most likely a mechanical problem if you can't narrow it down with the code puller. ECM (black box) might be defective, too. Could be as simple as a boogered up spark plug or a dying coil or a plug wire throwing spark to the block, through the insulation, damaged or not damaged. Have seen this happen even with new plug wires. If the simple issues are eliminated, then you might have to check the timing belt. The teeth or ribs wear on the belt and on the timing belt "gears" or pulleys under the cover and could slip one notch and throw off engine timing noticeably.

I'm sure the dealer could figure it out. They probably just couldn't duplicate the problem.

See an independent garage with a good reputation for diagnostic work. Do not assume anything when doing a diagnosis. Replace all the plugs. Check all power and control wiring (fuse to coil, PCM to coil) for damage, cuts, burn marks. Check the misfire data with a (expensive) scanner. It will show what cylinders are misfiring. Check each of the COP. Look for any burnt marks, cracks or wear. Check all the primary and secondary wire amperage (current ramp) with a scope on each coil to check if any of the coil is/are shorted.

https://www.youtube.com/watch?v=6kvYjYT1_mM