Engine Lack of power?

Any ballpark on what repair costs for something like that would be?

My 2004 Ford Escape; when I crank it up it idles high then idles really low & start to miss then you hear a hissing air sound. When I put my foot on the break & put into drive if misses more unless I idle the rpm to 1 the missing stops but the hissing is louder the more gas I give. Also when you drive it up hills it loses power and speed go's down to 5 miles cars have to go around me. But on open flat roads it's ok & the check engine light never comes on. I put new spark plugs in, new idle control value, EGR value, mass air flow sensor & new vacuum lines. Still no help. I even had guy at advance try and check for a code but there wasn't a code he said, so what can I do to fix my SUV?

Where would I look for the flex pipe? Does it come right out of the manifold?

Yes all that has been check too. Thanks for the reply back. This escape has me puzzled

I have your sollution for you! U said u have a hissing noise? Low power?
Clogged converter! Run the vehicle, get it hot, you wont have any exhaust pressure, if u step on the gas, no increased exhaust presure, at the tail pipe. You might get under the car and feel air rushing out from the flange connecting to the the converter pipe and also it will be extreamly hot.

Well, I'm thinking you are correct. On my way to the exhaust repair shop yesterday, I hear a sudden louder rush of air under the hood. Turns out the EGR valve had a hole in it, where the metal literally 'popped'. So I replaced the valve, and the associated solenoid, and now I am back to the original problem, of low power and a 'hissing' noise whenever I step on the gas. I am going to have a back pressure test done. Did the EGR valve pop because of the pressure from the clogged converter?

I had all vacuum lines replaced. You thank it could be the coil on top of the spark plug boots?

2004 Ford Escape, 3.0 V6, While driving, getting an air blowing sound when pushing the gas, and a lack of power, takes a lot longer to gain speed. It seems I have some kind of a compression issue.

But we're could it be at? The hissing sound to me is comeing from the passenger side. And more gas you give it louder it sounds. Like I said before when I crank it up; it idles high then starts idleing down past 1 rpm the really low and my escape starts to miss and hiss sound. Then I give it gas and get the rpm to 1 and it stops missing but the hissing air sound gets louder. But when I put my foot on the break and put into drive it misses and hisses more. Also when I driving it down the road and start up a hill it loses speed power; I will be running 60 miles an hour the time I get to the top of the hill with the peddle to the floor I will only be running 12 miles an hour. Also I can be driving in town and just lose all gas power I will have to stop and turn off my SUV wait a min or two then crank back up and have gas power. This is getting to me. I'm about to see if I can sale it.

First let me correct, the engine is automatic.
Not a silly question at all, b/c before this issue, I was getting cylinder misfire codes in wet weather along with some chugging, but then in dry weather the next day, no more chugging, and the engine light went off.
I bought new plugs anyway due to 95,000 miles, haven't put them in yet, hopefully tomorrow. Do you think the air blowing noise could be coming from the head?

Mark, thank you. That's the first bottom-line, common sense advice I have received regarding this issue. The guy at my local parts store said b/c the light went off, that no code would be read. I guess he was just being lazy. I am going to change the plugs, and look for any leaks, and go from there.
Take care

I just purchased the car, I changed the plugs because were gapped at.32, the car calls for.52-.56 so I set it at.54, I put everything back together gaskets were fine. Now when I start the car it shakes bad and engine rattles like a misfire or something. When I unplug the iacv the car should cut off but doesn't so I replaced it and that still didn't fix it. Then I sprayed brake cleaner everywhere and no change in idle so there's no leak.I'm or of ideas and there is no check engine light. The car is being horrible gas mileage and has no power/go at all when I push the pedal hard. Please help