Hey guys, its my first time posting on here and I thought id try to get some insight into what I should do for my car. Itll drive fine for awhile and then ill lose acceleration and itll go into limp mode. When I pull over and turn it off itll run fine for hours or even weeks sometimes before doing it again. Its throwing a p0420 catalytic converter code and p0400. The po400 code shouldnt be the one causing this but the po420 is telling me that my catalytic converter is clogged and its having a hard time pushing the expelled gasses out of the tailpipe. Seafoam in the gas tank seems to extend the time it takes before it goes into limp mode again and ive tried a single bottle of cata clean following the correct gas ratio as well. Ive replaced the mass air flow sensor and the o2 sensors and both made it run alot better for weeks to months but eventually it goes back to the same issue. My main question is if there is a cheaper or better alternative than taking my catalytic convertor off to clean or complete replacing it. My current gameplan is to just keep dumping cata clean in and see if itll burn up some of the gunk inside. Any help is appreciated
P0400: Exhaust gas recirculation flow malfunction might be causing the PCM to enter limp mode, you need to review manufacture specifics for your vehicle to determine if this is possible.
P0420: Catalyst efficiency below threshold, this indicates the catalytic converter is not as effective as it should be at cleaning the exhaust, it is unlikely to be “clogged”.
Repair the EGR failure, this might also correct the P0420 fault.