While I was at O'Rielly's today getting brake pads, I saw that they had an OBD I code reader available...So, I hooked it up to the truck and it pulled 2 codes. The codes were 54 and 74...does anyone know what these mean?
A little background: A couple of months ago I had a cat go bad and had to replace it. The truck also seems to flood at idle a bit, then when I hit the gas is stumbles or even stalls. I would think that maybe the codes indicate a bad O2 sensor, which would also explain the cat going bad. I believe that it is a rich condition that causes cats to go bad? Would this also cause the flooding? Hopefully this all leads back to an O2 sensor. Tell me what you think.

Thanks for the help guys,
Hunter

 

Oh yeah, it's a '90 F250 with a 351 if that matters.LOL

Thanks,
Hunter

 

yes running rich will kill your cats. b,c the air/fuel doesnt burn the fuel all the way so you are left with a sludge/film that coats the inside of the cats.

and yes running rich means you have more fuel in the motor then needed for the 14.7:1 a/f ratio And more fuel could mean flooding yes.

Cant say i know what is causing the problem tho....
-Patrick

 

54: ACT sensor signal is greater than the Self-Test maximum of 4.6 volts.

74: Brake On/Off switch not actuated during KOER test (user error).

Adrianspeeder

 

Thanks for the replies guys! Question though...what is an ACT sensor?...and could it be responsible for a rich running condition? I'm worried about the stumbling after idling thing. Don't wanna get killed in an intersection ya know. I'm thinking it's an O2 sensor cuasing the richness...also that burnt out the cat.

Thanks,
Hunter