P0171 & P0174 Trouble.

[saskexplorer]

'99 Ford Explorer, Ran like a typical Explorer with Intake Manifold Gasket problems,

Error Codes: P0171, P0174, P0135, and Cylinders 1, 2 and 3 misfiring.

Changed Intake Manifold gaskets, 171 and 174 came back on, ran a circuit test, cleaned MAF sensor and changed O2 sensor (passenger side, behind front tire.)

Now it runs worse than before, every 5-10 miles it begins to stutter and spit, and when I step on the gas, it does nothing. Then it snaps out of it and runs fine for another 5-10mi.

Where does my issue lie now? I still have Error Codes 171 and 174.
What should I try next?

 

[mjcoflesky3]

just had to do the ERG vavle and pipe on mine, now she runs like a top! 171 and 174 codes were gone after new pipe.

 

[swetrid]

What engine?

 

[saskexplorer]

4.0 V6. I believe its the OHC.

 

[unpredictable1]

When was the last time you did the plugs or wires?

Pull the plugs on 1 and 4 cylinders and see what they look like. (I have the same codes as you on my XLT)

On my sport she was sputtering and misfiring pretty bad and she was throwing a p0176 code. I pulled the #6 plug and it basically told me to change them all!

 

[2000StreetRod]

SOHC V6 upper & lower gaskets

If you have the SOHC V6 did you change the gaskets between the heads and the lower intake manifold or just the gaskets between the upper and lower intake manifolds? My leaks were mainly between the heads and the lower intake manifold.

 

[ucluglee]

I had the same codes on mine. I cleaned the MAF sensor and throttle body, replaced the throttle body spacer and spacer to intake O ring gasket, checked all vacuum lines for leaks, and also replaced the fuel filter. So far, knock on wood, no more codes.

 

[saskexplorer]

Yeah, I don't know.

It just seems funny that this would be the first time it would ever do it, after I replaced those items.

It was close to -30* C, so I suppose it could have been some ice in the fuel lines.

 

[Chris1973]

Had the same cod

'99 Ford Explorer, Ran like a typical Explorer with Intake Manifold Gasket problems,

Error Codes: P0171, P0174, P0135, and Cylinders 1, 2 and 3 misfiring.

Changed Intake Manifold gaskets, 171 and 174 came back on, ran a circuit test, cleaned MAF sensor and changed O2 sensor (passenger side, behind front tire.)

Now it runs worse than before, every 5-10 miles it begins to stutter and spit, and when I step on the gas, it does nothing. Then it snaps out of it and runs fine for another 5-10mi.

Where does my issue lie now? I still have Error Codes 171 and 174.
What should I try next?

Yes earlier this year and it was the camshaft position sensor.also changed the crankshaft position sensor because they work together.ran perfect after that.

 

[410Fortune]

thanks for helping out!

11+ years later!!
Don't worry I do it too