Truck has 120k miles. PO420 code. Any ideas what my first steps should be?

 

Do a Google search on the code for Ford or F-150.

 

https://themotorguy.com/engine-code-p0420-ford-f-150/

 

I was looking for what others on this forum have done for the fix. When I googled it there’s quite a few possible exhaust related fixes.

 

Official Ford code description.
When the PCM ...computer request CAT Regeneration test, for Temperature rise, and it results in less than a 40% rise, ......the code sets.
Can check for a difference in CAT Temperature first. If a large deterrence, its CAT replacement time.
This is somewhat a change in the usual code description for >Oxygen storage check< from the rear Ox Sensor, that is normally described for this code.
Bottomline is one can be a bit mislead from the older description.
It's just the way the Test is done on these vehicles and is much more accurate, for CAT specific health. If it does not heat up, it cannot work as designed.
Scanner check live data for 800* ++ running temps. Check both sides and compare.
120K miles put the CAT high on the suspect list.
Diagnose first, then act on repair.
Good luck.

 

Almost always a bad converter.

 

I actually got this text from my dealership. I’m wondering now what other recalls are out there I haven’t had checked out.

”Hi xxxxxxxx, this is xxxxxxxx. Your 2020 Ford F-150 may have PCM calibration issues that reduce emissions control effectiveness and trigger unnecessary alerts. It is really important to get this recall fixed and our team can do this for you at no charge. We have limited availability over the next few weeks, when are you available for an appointment?”

 

if thats the case have the update done, they should be able to tell you any other open recalls on the vehicle. They should also be able to use their computer (before they do the update) and look at mode 6 data - that will tell them the oxygen saturation capacity of the cat.

it could be a bad sensor - the cheap way to verify being to swap the rear sensors side to side, clear the code and see if it follows or not but as mentioned, odds are the cat is failing.

i would verify how close you are to the end of the emissions warranty - the closer you are the harder you need to push to have it verified if the cat is bad as Ford wants over 1k per side just in parts

 

When does emissions warranty run out? I also bought extended warranty for my truck.

 

i dont know, not sure if its changed over the years or if your extended warranty covers that as well. You're best bet is to find the paperwork and read it - emissions warranty will be in the owners manual and/or warranty supplement booklet. There's a ton of a different extended warranties so you'd need to look through that too.