i have a 1993 F150 5.0 4x4. auto trans.

i pulled my codes with a digital reader.i however forgot to warm the truck up first. i know that will make a difference, but i have a question about the codes i pulled. this is key on engine running. my key on engine off passed.

when it first came up it cyl 8 with no other info

code #10- cylinder #1 failed cylinder balance test

code #21- ECT out of self test range .3 to 3.7 volts

code #41- no HEGO switching detected. always lean on right side

Code#52- powersteering pressure switch always open or closed

code #77- no WOT test/ operator error.

i thought the WOT for 77 was only for the E4od trans?

as far as the other codes, i have no clue what they mean or what to replace/check to fix it. any help would be greatly appreciated. i'm going to run for codes again after i drive home from work in the morning so the tryck will be warm, and then update this if needed.

my trans shifts a little hard sometimes. my engine runs cool, but other than that there are no stutters, hesitation, she doesnt smoke or use oil or trans fluid. she idles smooth. she doesnt stall and the powersteering is smooth operating and doesnt even whine like our trucks are known to do.

 

*UPDATE*
im crazy impatient so i went and turned on my truck for 30 mins. to warm up to rerun the codes.

in this order they came up

cyl#8 again

10, 41, 77, 52...then started to repeat.

i also forgot to say that i DO NOT have cats on my truck and have not replaced my o2 sensor yet. would this be why im throwing these codes?

 

77 an 52...just disregard, but 41 you need to address. Cats wouldn't affect this unless you had an o2 after the cat an you cut it out. Think I'd get a new o2 in there an see if you still get the code.

As far as cyl 1...I think the balance test has to do with the injectors, I'm not positive on this and maybe someone will correct me. But it could be plugged if I'm thinkin right.

 

what is HEGO, or what does it stand for?

 

HEGO= heated exhaust gas oxygen sensor.

Except for the code listed for cylinder balance, all others are from operator error during self test. Engine needs to be at operating temp, ECT. Engine exhaust has to be hot for any EGO system to operate. Power steering has to be cycled (turning the steering wheel during self test) to functionally test the switch. The older systems (OBD 1) needed help during self test.

PS, forgot the goose test, code 77. (Rapid movement of throttle during self test)

 

i got the same codes after i let the truck warm up too. i'll clear my reader and let the truck warm up again before work and try again 3rd times the charm right? haha

 

ok, so i pulled the same codes this last time too. where is the HEGO, and can i just put a normal o2 sensor in there or does it need to be a specific type? i'm going to be replacing my entire exhaust system in the next month or two. adding cats, replacing my o2 sensor and muffler. i'm hoping that will take care of mileage slowly decreasing too lol