i have a 1998 f150 with 4.6 and 5 speed standard. its got a edge programmer in it. im getting lots of diag. codes.
P0443 evap code
P0161 h02shtr
P0306 cyl 6 misfire
P0171 bank 1 lean
P0174 bank 2 lean
now what the truck runs like.
It does alot of rolling before it fires, and if it does fire it feels like its running on like 2 cylinders it shakes and rattles. eventually it clears up and runs great. the odd time i can hear a small miss in the exaust.
driving down the road is a pain. i cannot give it more than 1/4 throttle or it bogs down and shakes,backfires then the cel light flashes. I cannot lug this truck at all. it has to be over 2600 rpm or it wont pull its self.
i checked the fuel pressure. in the haynes manual it says it should have 28-50. i only got 20. i pulled the vacuum line of the regulator and nothing happened. so i dont know if its the fuel pump or the regulator.
ANY HELP?

 

How is your maint on the truck? Plugs, wires, fuel filter? I have basically the same truck, well 4.6 5-speed anyway. Sounds to me like you have at the least a misfire, a vacume leak, maybe more. Everytime that my cel has flashed it was either a really bad miss.

As far as the drivability issues under 3k I would pull the edge off the truck until you can get it running right. It could be throwing to much timing at it with the lean condition, causing detonation.

 

I would start with the low fuel pressure. 20 isn't enough pressure and I wonder what the volume is. Would give you lean codes and possibly the miss. Either the problems in the filter or the pump is almost out. I would do a filter then recheck pressure. I think there was no change with undoing the vacuum to the regulator, the regulator sends what it doesn't need back to the tank on the return side. I don't think your getting enough fuel to have extra to regulate. Should have come up about 10 psi with vacuum off. Evap code and O2 heater problems won't give any running problems. I'd get the fuel within spec, clear codes and then continue with your diagnosis.

 

i forgot to add that i put a new fuel filter on it. I know bad o2 sensors make for hard starting. there just so expensive.

 

Have you pulled the plugs yet?

 

yea i pulled the easiest one i could. it looks not too bad maybe a little bit to lean(white) they were iridium plugs and had a quite a bit of gap on them. dont think that would affect the performance would it?

 

Was it even the one that was missing?

 

no it wasnt the one that was missing... i know but it was pretty cold out and i was workign outside at the time. i bought a new fuel pump and slapped it in last night. its a world of difference power wise. starts pretty normal again. i still feel a slight shutter and miss when i go over 1/4 throttle? the only codes i have gotten so far is the P0161 and the evap one. i dont know what to look at now. help?

 

Pull you plugs all of them and see what they say.

 

You can get Oxy sensors out on ebay for about $20 each or less. These are not Bosch but they do have plugs so easy to plug in and they work just fine. Autozone wants about $50 each and when you need 4, they are pricey.

I would first fix that misfire on plug 6. Don't fill your truck up with gas as the fuel pump (if that is what you need) is not hard to fix if the tank is near empty and not heavy when you remove it.