So I been dealing with the infamous p0420 code on my 17 journey its a 2.4L SXT. It's the only code I'm getting. I have replaced both 02 sensors, PCV valve, air filter, CAT is testing good on my scan tool. Had it at the dealing and all they could find was a cracked exhaust manifold and they replaced it. Got it back and the next day the damn light is back on. I do have the i/m readiness on my scan tool and before the dealer had it I only got a X/ not ready on EVAP. After the dealing I'm getting on FUEL and EVAP. When filling gas to full the code goes away and come back at about 3/4 tank. I've tried the injection cleaners and the cat converter cleaners with no luck. I'm at a loss here. Its scheduled to go back to the dealer in about 2 week unless I can resolve it before and save myself the cost of them doing the next repair. Any help would be greatly appreciated!!
