Question about 1998 Mercury Sable

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98 Sable, 3.0 showing codes: po171,po174 and po401 all together ?

This is getting dangerous for the wife and me. This car is dying at stops after it gets warmed up and after idling for around 5 mins. Sometimes now the engine is racing up after cold starting ?. The wife is afraid that we will be tail-ended because the car has died at a stop light or sign. The check engine light has come on twice, the first time we had to replace the catalytic-converter because they said the fuel filter had clogged up. The check engine light stayed off for only one day and then came back on. The parts store checked the codes and they read: PO171,PO174 and PO401 . This sounds expensive ?. We are both disabled and on a fixed income, so we can't afford to take it to the garage, again. Unless we get another Stimlus Rebate !. So does anybody have any ideas or suggestions, because we don't have a clue ?.

Thanks for any help that can be given:
Rev. Carl Wyant

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401 is the egr sounds like it is either malfunctioning our just is plugged with solid exhuast material (carbon). How well are you with a socket set? All you have to do with the egr is remove it (cold) and scrape the old metallic gasket material off (buy anew gasket before hand, $5) and turn the egr over and there will be air passages inisde. All you have to do is scrape the black soot from those passages, but dont spray any cleaner in there. Blow it out good, and put it back on. If it fails again with the same code, go to a self service junk yard and pull a used one off yourself, and try it on your car. The egr valves are fairly pricey new.
The 171 and 174 codes just refer to the left and right banks of the engine receiving too much air after the regulated amount is measured at the intake sensors (map, and maf sensors). You basically have an air leak, introducing more air into the combustion chambers and the combustion process is lean on fuel. Make sure all your hoses are connected to the intake, and are not cracked or broken, after that, its time to replace intake and throttle body gaskets, the gaskets are about $45 for the kit.

Posted on Dec 01, 2011

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These codes point to your car is running to lean, basically your air & fuel mixture is set incorret.

Posted on Oct 15, 2008


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