PLEASE HELP! NO ENGINE POWER

[reansor]

Yes, that is bizarrely coincidental. My mileage is at 154,010, too. My truck was driving fine before I changed the intake manifold, but running very slightly rough and the gas mileage was a little low. I discovered coolant in the #5 spark plug well when I went to check the plugs and found out that the intake manifolds on 4.6's are known for causing that. I also had a code for #2 bank too lean (from the manifold crack, I presume.) After I changed it, it ran awful and I got codes for a coil pack and 2 fuel injectors. I put some dielectric grease on the 2 injectors plugs and changed the coil pack and also changed the plugs with Autolite platinum and the fuel filter and it was good to go for about a week until my loss of power. It considered the cats, but it seemed too coincidental that both would go bad at the same time, but apparently not. I'm not sure what clogged them, but maybe it was just a long time coming and the fuel mixture being off was the final straw.

 

[reansor]

Yes, that is bizarrely coincidental. My mileage is at 154,010, too. My truck was driving fine before I changed the intake manifold, but running very slightly rough and the gas mileage was a little low. I discovered coolant in the #5 spark plug well when I went to check the plugs and found out that the intake manifolds on 4.6's are known for causing that. I also had a code for #2 bank too lean (from the manifold crack, I presume.) After I changed it, it ran awful and I got codes for a coil pack and 2 fuel injectors. I put some dielectric grease on the 2 injectors plugs and changed the coil pack and also changed the plugs with Autolite platinum and the fuel filter and it was good to go for about a week until my loss of power. It considered the cats, but it seemed too coincidental that both would go bad at the same time, but apparently not. I'm not sure what clogged them, but maybe it was just a long time coming and the fuel mixture being off was the final straw.

 

[reansor]

UPDATE:
I went ahead and drilled 3 1/4" holes in each cat last night and was able to rev it well above 2000 rpms. I just took it for a test drive and, although it sounds crappy, it runs and drives great. It'll at least get me to and from work until I get the new cats. www.carparts.com has the whole Y-pipe/cat assy for $430 delivered.

If you want to check your exhaust backpressure, here's the link for the tester Amazon sells:

https://www.amazon.com/gp/product/B...fl_title_16?ie=UTF8&psc=1&smid=A14X9047NAN5HZ

It's $38.99 and, unlike some that require drilling holes, this one threads into the O2 sensor sockets.

 

[ROBinGa]

Good news. I have researched a lot tonite and seeing lots of evidence that when coolant enters the cylinder and gets burned it kills cats for certain. I know that he drove it for awhile before I knew the manifold coolant leak was there. Then I started adding coolant to recovery tank and probably went through 2-3 gallons over course of a couple months. Entirely my fault so now will pay for it.

Interesting on drilling the holes. That may buy some time until I get things arranged and figure if I will try to tackle it or get a local shop to. The videos I've watched look like it's above my experience level but I also thought that about the manifold before I did it

Where did you drill the holes on the cat? From the rear side so it flowed or on the front side of cat since in theory it's blocked somewhere in the middle? Is it like crappy '68 Pontiac Catalina exhaust leak sounding bad or just loud? My son drives this car to and from high school and only 3 mile round trip. It's hurting to be down a car so if I can get it back on road even temporarily I may get my drill out. Thanks man

 

[reansor]

Good news. I have researched a lot tonite and seeing lots of evidence that when coolant enters the cylinder and gets burned it kills cats for certain. I know that he drove it for awhile before I knew the manifold coolant leak was there. Then I started adding coolant to recovery tank and probably went through 2-3 gallons over course of a couple months. Entirely my fault so now will pay for it.

Interesting on drilling the holes. That may buy some time until I get things arranged and figure if I will try to tackle it or get a local shop to. The videos I've watched look like it's above my experience level but I also thought that about the manifold before I did it

Where did you drill the holes on the cat? From the rear side so it flowed or on the front side of cat since in theory it's blocked somewhere in the middle? Is it like crappy '68 Pontiac Catalina exhaust leak sounding bad or just loud? My son drives this car to and from high school and only 3 mile round trip. It's hurting to be down a car so if I can get it back on road even temporarily I may get my drill out. Thanks man

I just drilled them in a row, front to back, about an inch and a half apart. I went right through the heat shield and his deep is a standard drill bit would go. There wasn't much point in doing them at an angle since it's all just sheet metal and really can't be directed. I just made sure they weren't going to blow out on anything critical. It's not real loud, it just sounds kind of ****ty, like I need an exhaust. Like I said, I only drove 3 small holes in each one and figured I'd probably have to drill more (of course it's a lot easier to drill more than fill the extras if I don't leave enough back pressure) but (3) 1/4" holes in each was probably about perfect. Changing the cats/Y-pipe, on mine at least, is all bolts--no welding. My exhaust from behind the cats is all fairly new and will unbolt fairly easily. Otherwise a hacksaw or Sawzall would do the trick. Unbolting the flanges from the exhaust manifolds will be a little harder, but some WD-40 well, I'm sure, do the trick.

 

[ROBinGa]

I think I will crawl under there tomorrow and scope it out if its all bolt on. Since I was having the misfire codes only on driver's side bank and also that's only where my coolant leaked into plug wells I will look at drilling holes only in that side cat first to see if it's the culprit, then if it accelerates normally I will report back about it. Are you looking into selling your cats to salvage like SyberTiger suggested? Also do you plan to buy all 4 O2 sensors or reuse those on new cat pipe assembly?

 

[reansor]

I think I will crawl under there tomorrow and scope it out if its all bolt on. Since I was having the misfire codes only on driver's side bank and also that's only where my coolant leaked into plug wells I will look at drilling holes only in that side cat first to see if it's the culprit, then if it accelerates normally I will report back about it. Are you looking into selling your cats to salvage like SyberTiger suggested? Also do you plan to buy all 4 O2 sensors or reuse those on new cat pipe assembly?

I'm definitely going to check into selling the old cats cuz I know they're worth something. I'll probably try using the old O2 sensors and if it runs good without codes, cool.

 

[imp]

After deciding I would replace the two cats and Wye pipe as a unit, if that became necessary, I saw that the LH side pipe to muffler flange bolts had no discernible hex heads left on them. Definitely would require cutting the bolts. Manifolds, another imponderable. Then, it became apparent the damned pipe/cat assembly could not be worked forward to lower it because the crossmember supporting the gas tank was in the way, so it would have to be lowered, I decided to beat on the offending cat, with eng. running fast. CEL went away, truck runs fine, no codes, 156K, original cats, new O2 sensors.

I'm just getting too damned old for this heavy-duty ****! imp

 

[SyberTiger]

I think I will crawl under there tomorrow and scope it out if its all bolt on. Since I was having the misfire codes only on driver's side bank and also that's only where my coolant leaked into plug wells I will look at drilling holes only in that side cat first to see if it's the culprit, then if it accelerates normally I will report back about it. Are you looking into selling your cats to salvage like SyberTiger suggested? Also do you plan to buy all 4 O2 sensors or reuse those on new cat pipe assembly?

If you are about to drill holes in the left cat you may as well beat on it like imp suggested as drilling holes definitely ruins the cat whereas beating on it first may or may not ruin the cat and you may get lucky like imp and not have to change it out.

 

[SyberTiger]

After deciding I would replace the two cats and Wye pipe as a unit, if that became necessary, I saw that the LH side pipe to muffler flange bolts had no discernible hex heads left on them. Definitely would require cutting the bolts. Manifolds, another imponderable. Then, it became apparent the damned pipe/cat assembly could not be worked forward to lower it because the crossmember supporting the gas tank was in the way, so it would have to be lowered, I decided to beat on the offending cat, with eng. running fast. CEL went away, truck runs fine, no codes, 156K, original cats, new O2 sensors.

I'm just getting too damned old for this heavy-duty ****! imp

Curious to know if you think you may have had a coolant leak on the intake manifold, ended up changing the intake manifold, then found out shortly thereafter you had a cat problem like reansor and ROBinGa have? Do you think you had coolant leaking into the intake ports and ultimately in the combustion mix?

 

[rocco123]

Should be easy enough to drill a hole and install a bung where needed. I've always wondered if you could test a cat uninstalled using a shop vac to see if it's restricted.
Thanks for the update info.

 

[rocco123]

Should be easy enough to drill a hole and install a bung where needed. I've always wondered if you could test a cat uninstalled using a shop vac to see if it's restricted.
Thanks for the update info.

 

[ROBinGa]

Yeah good point SyberTiger, I will go try to beat my cats and see if that helps first before drilling.

 

[ROBinGa]

Yeah good point SyberTiger, I will go try to beat my cats and see if that helps first before drilling.

 

[SyberTiger]

Yeah good point SyberTiger, I will go try to beat my cats and see if that helps first before drilling.

If after a good beating you hear what sounds like loose marbles rattling in the left cat that mean the honeycomb material started crumbling inside. The cat recycle buyer will still buy the cat if it's in the early stages of crumbling. i.e. the honeycomb with all the precious metals haven't been blown out the back.

 

[ROBinGa]

Well banging on my cats didn't do a thing..... still runs fine at idle but anything around 2,000 and it's restricted and loses power

 

[SyberTiger]

Well banging on my cats didn't do a thing..... still runs fine at idle but anything around 2,000 and it's restricted and loses power

You'll have to get together with imp to find out if the cats have to be super hot when you bang on them and what RPM.

 

[imp]

Curious to know if you think you may have had a coolant leak on the intake manifold, ended up changing the intake manifold, then found out shortly thereafter you had a cat problem like reansor and ROBinGa have? Do you think you had coolant leaking into the intake ports and ultimately in the combustion mix?

@SyberTiger
Actually, the engine has never been touched, save for new plugs about 50K ago, and the Fuel Pressure/Temperature Sensor twice. The cat problem became suspect due to constant repeat of DTC "HO2S Heater Resistance, Bank 1 Pos 2". Erased, that code returned on the same climb uphill coming home + - 1/4 mile of the same spot! About 10 times over several weeks time. Other driving, no code. I decided some repeat combination of engine speed/load/cat temperature was causing it, after bypassing all the wiring between the sensor and PCM after checking continuity, heater resistance, then finally all new O2 Sensors; new one did the same thing. Couldn't be the sensor or the wiring, so.....cat somehow caused it. Beat on it, DTC gone, now been 1000 miles. imp

 

[Paulyy___g]

Just wanna give a big THANK YOU to REANSOR for starting and updating this thread as it helped me out big time!!!

Long story short, had to replace my fuel pump assembly when my 2002 4.6 V8 broke down after losing engine power. Engine wouldn't start so when going to replace my spark plugs I realized I needed a new intake manifold as I had coolant leaking in plug 5, thermostat housing had a crack. So after changing the manifold I still couldn't get the engine to start. After stumbling upon this thread after throwing new ignition coils and a crankshaft sensor at it, I decided to give it a go at beating on the cats while forSCAN was doing its thing. Don't ya know it started right up! I'm still gonna need to drill some holes as I can't get it above 2000rpms without it stalling out but that's tomorrow. Two long months later and the road ahead looks good!

But anyway thanks again guys, this forum is amazing!

 

[ROBinGa]

Sounding good Paulyy. I ended up having my local shop replace the whole cat assembly after they towed it in and hooked it up and found clogged cats by back pressure test. The Explorer runs very well now as I expect it should with new intake manifold, plugs, all new coil over plugs on driver's side bank. it just couldn't breathe, like someone putting their thumb on your snorkel when you were a kid in the pool. Hope you get yours breathing right again and back on the road