So heres the story..........'02 Escape, 179K miles, just had the oil changed 2 weeks ago, ever since then I've smelled oil burning when the car starts up and every now and then after exiting the car. Also have had the check engine light on intermittantly for the EGR insufficient flow for the past few months. It comes and goes whenever it wants. Today Wifey called me and said something was wrong with the car, I drove it home (about 26 miles). The car runs fine as shifts through the gears, but as soon as it gets a load put on it, it cant pull hard like it used to and it gets a high pitched/squeely whistle similiar to a turbo thats spooled up. Its hard to say where its coming from but from what I can tell I'd say somewhere under the hood near the glove box. (thats the only way I can think of to describe it) Theres a big long hill right outside her work that I wasnt sure I was gonna make it up. Car just didnt have any power and couldnt decide what gear to be in as RPMs were too high in a lower gear but wouldnt pull in the higher gear. Car pulls hard off the bottom but falls flat in the midrange. Anyone have any ideas? I was thinking maybe clogged cat but what would the whistling sound be?

 

Dang, 94 views and no one has any ideas? Clogged cat causing back pressure to make the EGR valve whistle? whatcha think?

 

It sounds like a plugged catalytic converter to me. Have you checked your EGR valve for overheating or damage? An excessively hot EGR valve could indicate a restricted rear manifold catalytic converter. Checking fuel trims on that bank with a scanner might confirm this. If the EGR isn't getting hot, then it could be the rear catalytic converter under the passenger's floor board. That was what happened with my Escape.

 

Started trying to troubleshoot the whistling noise, has turned into a screech like the serp belt squeeling. Getting worse. Does it in the shop also when revving the motor, stops when it comes back down to idle. I pulled the belt off and ran the motor, its still there so its not the belt slipping and obviously not an altenator, pwr steering, AC or idler pulley. Sound seems like its coming from that side though. No codes showing on the tester. Car is running worse, idles fine but even in the shop in park, when I throttle up it wont build rpms after 2-3K rpms, doesnt really hesitate or stumble, just wont rev out through the rpms, and wont even hit the rev limiter anymore. EGR has no visible damage and did not get hot when I ran the car. Where to go from here?

 

read on another forum about a possibility of a clogged cat causing the ex manifold gasket to blow = loss of power & squeeling noise? Sound like a probability?

 

Usually it is one of the front cats that fail, and often break up and plug the rear cat. shake the exhaust and see if you hear anything in that area.

Often, a plugged cat will result in the DPFE hoses being blown off and/or burnt. Make sure you check those.

Front cats being plugged, remove O2 sensors and see if engine revs better and/or use borescope to inspect. Beware of hot exhaust from the holes causing damage to other components. Don't drive it like this, just a quick in-bay test.

 

shook the rear cat and tapped on it a bit, doesnt sound like anything rattling inside it, DPFE hoses are connected and look ok. I'm a little hesitant to pull the front cats off until I can be more sure of a probabillity of it being the problem. Rear cat looks easy to pull so long as the bolts come off easy. Priced the cats and holy crap they are spendy. What are your thoughts on removing the rear cat all together and simply replacing it with a tube? (if its clogged) Any flow/emissions problems with that? Still stumped on the squeeling sound, I have no idea where to go from here with that.

 

The squealing noise can be caused by the exhaust restriction, causing the blockage to act like a whistle with the engine running. My blockage wasn't bad enough to do this, but I was told by a former mechanic that it can do it.

Deleting the rear cat won't hurt flow; but you are removing an emissions device, and depending on your state inspection laws, that can impede your ability to pass the state safety/emissions inspection. Just saying.

FireMe's comments were good ones. Pulling the upstream O2 sensors (I know it doesn't look like a fun job) one at a time and running the engine is a pretty good way to determine if the front cats are plugged. If your EGR valve and DPFE tubes aren't being impacted by the problem (via heat or pressure damage), then I'm more inclined to believe that the rear manifold converter isn't the problem---but the front manifold converter could still be shot.

With mine, I was ready to blame the rear manifold cat and only the rear manifold cat because of fuel trim data. However, upon dropping the Y-pipe to get a look inside all 3 converters, I saw that the manifold converters looked almost brand new at the outlet ends (element nice and white, no cracks or carbon). The rear converter, at the inlet, was a different story. Although not completely blocked, it looked dirtied up with carbon and a little plugged around the edges. So, I drilled a few holes through the element inside the converter, put the Y-pipe back up, and took it for a test drive. That solved my acceleration problem.

You're going to need to do some more invasive troubleshooting to determine where the problem is. Pull the O2 sensors one at a time, per FireMe's advice, and also visually inspect the inlet side of the rear converter. You should be able to narrow it down pretty quick that way.

And yeah, those cats are expensive all right....Cole Muffler quoted me $1100 EACH to install new manifold cats. If you can do the job yourself, though, Best and Fox sells them as a pair for less than $600. Includes gaskets. Hopefully yours will check out fine, though. That's not a fun job.

 

well I cant say the EGR isnt being impacted bcuz we've been having the check engine light come on intermittantly for EGR insufficient flow, not sure how that would tie in if theres a blockage in the exhaust. I would think I'd get excessive flow with a blockage......er......which side of the cat is the EGR port?

 

The EGR code could be the DPFE sensor. Those are known to need replacing.

I don't know what the noise is, but it has been reported that a bad IAC can cause a loud noise, kinda like a jet or something.

 

well the sound is getting worse, more like a belt screeching real bad, but the belt is still removed. I disconnected the front of the rear cat and there was some debris from one of the the fwd cats, not sure which one yet. I started the car and it was very quiet for a bit then a huge surge, a pop, and then vroom! Must have cleared out a blockage in the Y pipe or something, I was wondering why it was so quiet with the exhaust disconnected. Now its loud but hard to tell if its the fix. I vacuumed out the rear cat, there was ALOT of powder that was sucked out of the honeycomb. I reconnected the rear cat and everything is back to not working right so I'm gonna assume that cat is fubar'd. Going out to work on it some more. Still cant figure out the squeeling noise.

 

Yeah, one of the front cats have crumbled if you had that much debris in the rear one. The rear one is likely plugged beyond saving. That squeal doesn't sound like an easy fix...have you been able to track the noise down to a specific area of the motor?

Edit...have you checked the water pump, belt, and tensioner? They're located on the driver side of the motor, opposite the side with the serpentine belt and everything else.

 

In an attempt to troubleshoot, I drilled out six 3/4" holes through the honeycomb on the rear cat, vacuumed it out and reconnected. Car runs great now. Squeeling noise was front exhaust manifold leaking air causing it to squeel like a kid with adhd playing a recorder. Can hear a small exhaust leak on the front side now. Wifey can drive it for a lil while till I get it fixed. Pretty sure whichever front cat went bad has no guts left as the mesh that holds the ceramic in came shooting out in a wad when I disconnected the rear cat and rev'd it up good.

 

just FYI: my neighbor had the exact same symptoms ...theres a little EGR hose under the intake that collapses/splits and that was his problem. you have to take the intake off ...at least i think you do, you may be able to get at it from underneath, at least enough to see if thats the problem. good luck

 

Going through this exact type of scenario. 2002 2WD 3.0

I get a minor screeching sound.

It began with a new set of valve cover gaskets, new timing cover gasket, and new oil pan gasket. Plus the trans valve body gasket....and fuel filter.

Starts up, no codes. Has a shake to the idle. Which gets worse as it is driven. Noticeable lack of power. I checked HARD for vacuum leaks....pulling upper intake multiple times. every source of air going in was checked and hoses that were suspect were repaired.

Changed all the plugs.

Verified all sensors were plugged in. Replaced the MAF with a used unit. Ran compression check and fuel pressure checks. All is good.

Took for drive this morning. I figured a longer drive will cause a code to pop up. 3 miles in the truck loses tons of power and won't rev past 3k..... slowly it loses more and more power. I parked in a parking lot and it has a top speed of 3-6 MPH.

Walked home. Funny thing is, walking gives you time to think. Everything now points to a plugged converter.... no clue how what I was doing had anything to do with making a converter fail.

Going to load up the trailer and tow it home now and drop the crossover pipe and see what happens.