Hey guys,
I'm new to this sort of thing, Ive never owned a truck and inherited a 1997 ford f-150 V6, I apologize in advance, I have never posted on a forum like this before and don't know if I'm looking in the right place.
I wouldn't consider myself that knowledgeable about trucks but I know its running a little rough. The truck is super clean and looks like it was just used for a play around the city. I got a scanner and it read a few codes,
if anyone can help me out that would be greatly appreciated.

P0153- 02 sensor circuit slow response(bank 2 sensor 1)
P1151- powertrain, MFG, fuel and air metering, fault:51
P0300 random/multiple cylinder misfire detected
P0171 system to lean bank 1
P0174 system too lean bank 2

Thanks so much in advanced

 

Swap the upstream O2 sensors to see if the banks change. The misfires could be the results of spark plugs, ignition coil, and spark plug wires amongst other things. These items could be attributing to the p1151 code which I would solve for first to see if the other issues clear up. The p0171 and p0174 I would solve for last as that could be caused by the other codes. Would not be a bad idea to have the truck smoke tested for vacuum leaks first. With yours being a 97 I would check the timing chain cover near the water pump to ensure it's not in need of replacement as that year had an issue with hydrolocking due to the pump rubbing there. Hopefully some far more knowledgeable members than I will post soon. In the meantime, change the fuel filter and spark plugs as part of your new to you maintenance along with the other filters and fluids.

 

Do not begin swapping any parts positions.
It won't prove anything but create confusion with you already not knowing what this is all about.
All the codes point to the same fault..
Address the likely cause.
Your code 1151 description is all misleading.
Codes 1151 and 153 both point to the response of bank 2 driver side front Ox sensor poor response or a Lean condition detected in the exhaust gas composition.
Codes 171/174 are also generated by the both banks sensors.for the same reason. To much Ox in the exhaust gas content.
You are beginning to see the commonality of the codes to the cause.
Bottom line is the intake tract has a vacuum leak creating the Lean condition the Ox sensors are detecting at the output of the engine exhaust stream.
It's the only way the system has to detect the condition.
Why the codes set: The Ox sensor signals cause both long term fuel tables to shift>>>>>RICH<<<<< trying to 'correct' the condition. Notice they move in the opposite direction.
When these tables shift + 25%, they set the codes you have. 171/174.. Plus means add fuel.
The 300 code tells you the system also detected random cylinder misfires as the result of the fault. How this is done is by the Crank sensor actually measures the crank rotation time for every cylinder to detect the misfires when the rotation does not occur within a normalized time or the rotation time becomes to long.(lack of enough cylinder combustion pressure.= a misfire). Again, there is no other way to detect this excepts by specific codes such as 30x r 35x codes assigned to each cylinder and detected by the Crank sensor.
Do you see how it all ties together?
The system is a computer, therefore uses Logic functions and decisions built into the software program to let you know via codes.
Then you must have some idea how the system reacts to a fault that is allowing un-metered air into the engine.
Look for the vacuum leak as 99% of the issue, first.
The truck after all is 23 years old no matter how good it looks.
This is why we don't swap parts at the beginning of a repair process. What would be a useful benefit? Like if you go the your Doctor with a Toe that hurts, he would not swap Toes first.
Hope this offers you a start.
Good luck.

 

I'd reinforce this recommendation. The early 4.2L engines were notorious for intake manifold gasket and isolator bolt leaks as well as the PCV leaks common to all the modular engines from that era.

 

Does 97 V6 have isolator bolts? I always thought aluminum casting plenum (97 and 98) didn't have isolator bolts. Am I confused?

There are a few rubber elbows that tend to go bad and cause vac leak. Two difficult-to-reach ones are located at 1. directly under the throttle body and 2. Near pcv on the pcv hose. I could not see them. Only feel. For 1, follow the short vac hose (3-4 inches long) running straight down from the throttle body.

 

Could easily be me. I'm going off memory which is faulty these days (and not getting any better...). If someone with hands-on knowledge can chime in, that would be great. I just kind of lump all the early 4.2L issues together and I don't know the more subtle differences between early and later variations.

 

Taking the majority of your posts into account I would say, "all evidence to the contrary."

 

You are not talking about me, are you? 😄 Since I had and still have elevated long term fuel trim, I have looked into vac leaks. I remember looking for isolator bolts on my cast aluminum air plenum but couldn't.

 

You could be correct, it might only be the 4.2 with the plastic intakes. Mine is the only one I've had to work on and forgot that the earlier 4.2 had the aluminum intakes.