2015 Explorer Police Interceptor 3.7L catalytic converter issues

[Jessilee]

I have 2015 Explorer Police Interceptor Utility 3.7L. I will start from the beginning. About a year and a half ago I started getting an alert that would say "check fuel intake" I did all the recommendations to fix this it said in the manual, and a few days later it would go off like it said it would. During this time, I started to get really frappy gas mileage, and noticed it didn't have the pick up it used to. While idling it almost sounded like it was idle was dropping. Check Engine Light came on. So about a year ago I put in two new catalytic converters. Not OEM parts. A ywar has gone by, and same issue. Now throwing a code catalytic deficiency p0420 p0430. We took out the year old converters one you could shake and ir was rattling. So we are at a stand still here. OEM parts are now up to a ridiculous amount, and im leery to purchase them if they are not going to even last a year. Does anyone know why this would be going on, or what would cause these converters to be going out?? Any help here? This is killing me. I'm driving my husband's 1 ton duramax and the fuel cost is breaking me. I need my other vehicle. I need advice desperately. thank you!!

 

[Jessilee]

Apologies for my spelling errors, as well as wanted to add- I've put in new coils, spark plugs, I did the transmission fluid, o2 sensors, front and back ones. Back pressure gage reading was in red.

 

[peterk9]

Here are the OEM ones, I think. Exhaust Manifold for 2015 Ford Police Interceptor Utility | Auto Nation Ford White Bear Lake
Being they are Ford replacement parts, the are warranted for 2 years, unlimited mileage. On some parts the warranty is longer.
Ford's prices are higher than those shown in the link.

Peter

 

[Jessilee]

Here are the OEM ones, I think. Exhaust Manifold for 2015 Ford Police Interceptor Utility | Auto Nation Ford White Bear Lake
Being they are Ford replacement parts, the are warranted for 2 years, unlimited mileage. On some parts the warranty is longer.

Peter

The ones I bought that we not OEM, did have the year warranty. However, they require you to buy the new parts first, than send back the ones claim to want warranty on. It feels like they can than deny them and I've ready purchased the new ones... just seems shady. And those also went up from $600 to almost $1800 for 2!!