2006 Mercury Mountaineer - Idles fine. Sputtering/losing power while driving
Over the past couple of years I would notice a stutter in the engine while driving.
Progressively got worse. That stutter turned into knocking and acting like it would die.
While not in drive, it idles fine. Give it gas and it revs fine. While driving though, I get
the stutter, then the loss of power and have to pull over as it knocks and clunks and
just won't go. Mechanic replaced fuel pump and filter. Said he saw a loss of fuel
pressure. Drove it today, back to the same ol' problem. Any ideas? Can the exhaust
system/catalytic converter cause this behavior? O2 sensor?
Could be converter stopped up,causing it to flood it self,have it checked,and if that is ok,do a compression check on the engine cylinder,s,
Ditto what T_S_T said. Yes the converter if plugged can restrict the exhaust flow to the point it will not run at all.
Any CEL's on?
No CELs. Weird. If converter is the issue, wouldn't it do it when idling and reving while not in drive? Any chance it could be some sort of fuel sensor? (since there is loss of fuel pressure noted)
It could be a combination of things. Fuel pressure regulator comes to mind.
did you ever figure out what it was. my old oine did it an it was just the spark plugs.
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