Losing Engine power
 

My 2002 Sable GS has 108K miles and has been great until now. It just loses power and dies at any time. Restarts immediately, but I'm going to get rear ended soon. No matter if I'm driving 70 or 20...it's done this 5 times now. Scheduled for major tuneup tomorrow. The Mechanic's machine says it's running fine - someone told me it also could be an ERG valve that it needs. I've never heard of that part. What does it do?

I travel frequently to Chicago and scared that the tuneup won't cure it. I'm going to get killed. Help!

EGR (Exhaust Gas Recirculation) valve controls the flow of exhaust gas flowing into the intake to help reduce emissions by re-burning (so to speak) the unused fuel. If it's a 2002, it would be showing the check engine light (Malfunction Indicator) and you'd be able to read codes from the computer about the EGR system.

When it dies like this, does the radio drop out (if you're listening to it, does it stop playing for a second)? If so, then you have something that is causing a momentary short and killing power to the vehicle altogether. This could be many things and usually ends up being the positive wire to the starter that has rubbed on some part of the frame, causing the insulation to be removed, and is making contact sometimes and causing a short. It could also be a momentary voltage regulator issue or some loose connection to the alternator and/or battery. There's numerous other things that can cause this to happen to. One thing for sure is that the engine probably needs new plugs if they've never been changed. I've also seen on a few older versions that when the engine mounts get worn out, sometimes the engine will rock and lean on the alternator pulley, stopping the alternator and that can cause issues as well (you would probably hear a squeal from this though as the belt would be rubbing against the pulley but not turning it). Exhaust restriction can also cause this (melted catalytic converter - the inside... not usually visible from the outside, rusted out muffler that occasionally flaps a large piece up to block the exhaust - this is what cause my muffler to explode - that was an interesting day).

I actually am thinking that checking the muffler first might be a good option (after checking the easy to get to wiring for issues - always do the free stuff first). If you see rust around the drip hole in the muffler, it might be a good idea to get a pro-flow (straight through) type muffler that will prevent this kind of blockage in the future.

Sable full tune-up didn't help
 

Got my car back late Friday. Didn't drive much Sat. On Sunday it acted up again and cut out on me about another 5-6 times....at slower speeds thank goodness. Got rough and chugging a few times while driving at 40-50 mph.
Just spent $450 on this tuneup for nothing! Spark plugs, wires, PVC valve, fuel filter, oil change, oil filters....and whatever goes with major tuneup.
Today they couldn't get it to cut out. Now they want another $350 for a fuel pump and 2 fuel filters, charging me for only 1 hour (out of 3) labor. They said it registers low pressure. But, they still aren't real sure of the problem since they can't make it happen. Told them to drive it more.
Not sure what I should do. Take it for a 2nd opinion?

I bet it's clogged injectors along with any other issues. I'd run some injector cleaner through it. Had the same issue with an acura legend... engine would bog when you hammered it or when you got above 60mph. Injector cleaner helped lots.

Now if a fuel pressure test says low pressure, then that would be a major cause of all of this and a new fuel pump would be needed (along with cleaning the crud from the bottom of the fuel tank so that the new pump doesn't get gunked up).