CEL Still on, what Now?
 

Hello G Fam. Hope everyone is staying safe and cool out there. 12/20 replaced left V.C, all 6 s.p's, afterwards, car had no start, but cranked. Was told I needed a ecu; replaced that, all s.p's, again, w/denso & put on a blox 5/16 p.s., 2/4/21. No problems, ran fine. Now 3 wks ago cel popped up after reaching 80mph; Obd ll codes P00300 & 456 showed. Car was shaking like crazy, cut off twice, while trying to get back home, 30mins away. Was told I needed to get new coils and supposely a smoke test was done, where no small leak was detected. Got the 6 hitachi coil pks, 6 ngk iridium. He, same mechanic, changed them those out. Upon picking the car back up last week, cel came back on 15 miles later; no p0456, but p0300. I am so over my (G)eorge right now, but I don't want to give up on him just yet. Oh I forget, mechanic stated the TB was cleaned & show me where a rip was in the air intake coupler. Just put a ztube & couplers on yesterday, poured in seafoam filled, George up. After putting full tank gas, erased code po300 drove 10mins to gas station & back home, no rough shaking, but codes p0300 & p0304 popped back up. I can't drive for fear of messing things up farther. Forgive me for this long text. Wanted to put everything down. Thanks for any positive feed back. G-loveroutofBaltimoreMD

Well the car is telling you there is a problem with cylinder 4 spark, I suggest you get a new mechanic since he's snowballing your issues which usually means one of two things.

A. He's doing it on purpose to defraud you of more money.

B. He's incompetent and causing more problems while trying to fix stuff.

As for the issue at hand, unplug the coil pack, inspect the harness for any damage to the wiring or harness, pay close attention to the pins inside the harness. Remove the coil pack and inspect for blistering of the epoxy resin encapsulation on the top, scorching of the spark plug well tube, or corrosion of the contact spring inside the well tube. Also check your spark plug well for any oil accumulation BEFORE removing the plug which is indicative of failing valve cover well tube seals and will cause a misfire when oil level rises enough to screw up spark. Also inspect the spark plug for gap and burn condition.

P0456 has nothing to do with any of that, it means there is a small leak on the EVAP system.

Thank you cleri670 for responding. I 🏃‍♀️ because I work to hard for my $$'s to not get what I paid him to do. Tomorrow, pending no Tstorms, my brother & I will check those parts out that you suggest. I post the result afterwards. Again, thank you.