Tlynn420

My brother has a 2004 F150 that suddenly quit the other day while he was leaving work and wont start since. Code read it today and the result is PO-420 which comes out to Catalytic Converter which can be a lot of things I have learned lol.


My question is does this make sense? Because most info I have found the vehicles still run but show other symptoms.


My uncle said try disconnecting battery for a bit then re try but that didn't work.




From your experience could the 2 still be connected or is it likely something else as well?


Any Ideas or Suggestions greatly appreciated. Thank you for your time.

Jack-Daniel

I had similar symptoms on a vehicle once. The catalytic converter had crumbled and plugged the exhaust, I disconnected the exhaust,in front of the cat it started and ran fine..(loud though)

chickenwire

Can also remove the upstream O2 sensor to test (though I don't know how easy it is to get at it.) If the exhaust is plugged as Jack says above the engine won't run. If it's partially plugged it may run, but it won't run well.

gone postal

Define "won't start".

Won't turn at all, Tries to start but won't, no ignition whatsoever, there are many "no start" conditions.

Got to have spark, fuel, air and compression. If one of those is missing, it won't start.

vintageman

Check the FPDM that is on the crossmember above the spare tire, if it is mounted flat on the crossmember then he has the old version and it will probably be corroded and have holes in it when you take it off. The new ones have spacers to lift it off of the crossmember and help prevent corrosion. It is a known issue with these trucks. Replacing it probably takes about 5 minutes once you get the spare tire down, so its a quick check, new on is probably around $100 at an autoparts store or about $60 online. I know that the code was for the cat but the code could have been pending before and not related at all to the no start problem. Good luck


Tom

HulluCorn

^^x2

Tlynn420

Thank you all for your replies! My Uncle is convinced its the Fuel Pump but I trust the code more haha we shall see! My brother is going to check FPDM first off as he was thinking of that originally and its a easy check!


If that is not it he is thinking the exhaust could be plugged as mentioned. Thanks again I will update what it is when we solve this!!!

Tlynn420

Sorry about that, it tries to turn over but doesn't. It doesn't turn over and then stall it just never turns over at all! I believe that's why my Uncle so set on it being fuel pump but wouldn't a code come up for such a problem?

techrep

iTrader: (1)

Check the FPDM first...very common problem ... this little module will not allow the fuel pump to run.. it is mounted to the frame rail and corrodes and breaks open and shorts out, located above your spare tire.

Dirttracker18

This is very hard to understand what you are saying so lets try to clarify.

It attempts to turn over but cannot?

Certainly plugged cat as it will not allow the exhaust to get out, like trying to blow into a empty pop bottle.

If it is a fuel pump issue the truck will turn over but not start or may attempt to start and then stall right away