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Discussion Starter · #1 ·
I have searched this forum and others, and I'm coming up with multiple causes from sensors to gaskets etc. I have had this happen probably 8-10 times in the last two months with the last week being worse. When I brake coming to a stop sign or light the idle drops really low and sometimes stalls or sputters. It has happened with the engine being cold and warm, the first time it happened I was on a road trip so I thought I got bad gas and switched to higher octane and didn't have any problems for a few weeks.

Only once has the CEL came on and was on for only a half day or so, no flashing CEL or limited power nothing. Where should I start? Any ideas on cost?
 

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Sounds like a vacuum leak / bad diaphragm internal to the brake booster.
 

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Can you cause a still by pumping the brakes, or is it just at random times while idling? I'm guessing vac leak, where is the main question. If you're getting unmetered air into the int system (air that biohazard the MAF/MAS) it will cause such a lean condition that the motor stalls.

~psguardian
 

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since there was a check engine light that came on go get it check and see what it was it will most likely be a lean code but usually when you hit the brakes and the engine dies it is because a large amount of air has entered the engine and the fuel mixture is to lean to keep it going and it stumbles or dies
 

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You can test this by pulling the vacuum line from the booster and plug it. FAIR WARNING! The brakes will be extremely hard so be prepared. If the symptoms go away, your booster is leaking.
 

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Otter said:
I have searched this forum and others, and I'm coming up with multiple causes from sensors to gaskets etc. I have had this happen probably 8-10 times in the last two months with the last week being worse. When I brake coming to a stop sign or light the idle drops really low and sometimes stalls or sputters. It has happened with the engine being cold and warm, the first time it happened I was on a road trip so I thought I got bad gas and switched to higher octane and didn't have any problems for a few weeks.

Only once has the CEL came on and was on for only a half day or so, no flashing CEL or limited power nothing. Where should I start? Any ideas on cost?
I had similar symptoms on my Ford E-150, but it would also try to die when I put it in reverse to back up. Found out all these are pretty classic symptoms of a failing Torque converter in the tranny, at least in the E-150 vehicle line. (The trans conveniently weighs over 200 lbs alone)
 

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It'll get worse. The CEL will happen soon. Has your Trooper had the intake gasket changed yet? I'm betting it's due. Don't despair. It's an easy DIY job with the most basic of hand tools and a bit of patience.

Let your engine idle and spray the engine with carb cleaner. If the idle changes when you're spraying the intake gasket area you'll have your answer.
 

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Discussion Starter · #8 ·
I put a code scanner on it today and came back with a P401.

To clarify it stumbles when braking and has came close to stalling, but the only time it has stalled is when putting it in park. When it starts to stumble I can lightly hit the accelerator and problems go away.

I have had a flashing CEL a few times over the two years that I have owned it but only a handful of times. I'm not sure that last time the gaskets were changed I'm the third owner I have most of the repair records and will check it has 143XXX miles, I'm not sure when the oversized tires were added so it's safe to add say 7% to the mileage.

Thanks for all the replies!
 

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Discussion Starter · #9 ·
Replaced the EGR no issues as of yet, the EGR did have a bunch of build up on the back side so something was failing either the gasket or the valve itself.
 
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