PLEASE HELP! NO ENGINE POWER

[Paulyy___g]

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

Thanks a lot Rob, I forgot to thank you as well, the questions you asked helped me out also. I'm planning on changing out the whole assembly also as soon as I go back to work in the spring, hopefully drilling some holes will hold me over until then. Probably gonna fail inspection a few times before then but oh well lol.

 

[ROBinGa]

If you had trouble with driver side plug and coils I would wonder if you try drilling hole in that side cat first and see if you relieve your pressure. Then if no success try the larger bigger downstream cat with a hole or two. I just wonder if the coolant that got burned in engine on that side fouled only that cat since the exhaust manifold from that bank goes to the smaller front cat before the tubes combine and then go into the larger back cat. Maybe you can detect which cat is clogged this way and verify if as we suspect that the leaking intake manifolds are causing cat failures too. Not endorsing the drilling technique in any way but if you plan to do it maybe you can do it in stages to see what works

 

[imp]

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.

@Syber Tiger @ROBinGa
Well, the old imp started a whole lot of ****tin' in the barrel with this one! Refresh memory: Had recurring HO2S "Heater Resistance" Pos 1 2" code (only). Erased, returned, over and over. But, different symptoms than you guys here, truck ran just fine, good idle, good power, good fuel economy, BAD CEL PITA. Cat moderately hot, not road temp, wife ran eng. at 2500 while I hammered about 12-15 times on the heat shield surrounding the cat. Drove it. No CEL! I figured fine soot broken loose could be blown through and out, so had a piece of cardboard suspended in front of tailpipe. No marking on it at all. Well over 1000 miles now, no CEL. imp

 

[Paulyy___g]

If you had trouble with driver side plug and coils I would wonder if you try drilling hole in that side cat first and see if you relieve your pressure. Then if no success try the larger bigger downstream cat with a hole or two. I just wonder if the coolant that got burned in engine on that side fouled only that cat since the exhaust manifold from that bank goes to the smaller front cat before the tubes combine and then go into the larger back cat. Maybe you can detect which cat is clogged this way and verify if as we suspect that the leaking intake manifolds are causing cat failures too. Not endorsing the drilling technique in any way but if you plan to do it maybe you can do it in stages to see what works

So I drilled my holes today and it is idling great and engine revs beautifully. I drilled 3 holes with a 1/4 bit going down the first left or driver side cat in the front, middle, and back. Before drilling into the right side cat I started my engine and hit the pedal and she roared like a champ so I didn't feel the need to drill any holes in the right side cat. I too thought about how only the left side of my intake had the coolant leak and thought that the left side cat stood the better chance of being clogged up which was keeping the engine from starting. So problem solved for now, I must admit that it sounds awful as you can basically hear a crackling sound coming from the cat and can see the exhaust shooting out from it but for a temporary fix until I get another one put on I can deal with it. Thanks again everyone and hope this helps someone.

 

[ROBinGa]

Excellent. So that does sound like you have confirmed the coolant leak into combustion mixture from intake manifold, which is so common on the 4.6, clogs that driver's side upper cat. This may be very helpful for many people who will have these symptoms in the future. It can be very frustrating to have your car run normally one day and the next seem catastrophic. Nice work Paulyy

 

[Paulyy___g]

Tell me about it, I was chasing this problem for over a month (in my spare time)

 

[SyberTiger]

Well, I'm hoping I'm free and clear of this problem. My intake manifold was leaking coolant but I'm hoping that none of the intake ports had a leak on the intake manifold. I did have a very rare occasional misfire cod but hopefully that concerned a coil pack short due to fluid buildup in the #8 cylinder.

 

[reansor]

UPDATE:
After driving my Mountaineer for over a month with my holes drilled in the converters (sounded like sh*t, but drove fine) I was finally able to replace them. I got the whole Evan Fischer Y pipe from from carparts.com for $432 delivered. It was a pretty straight forward bolt-on install, but getting some of those 13 year old bolts off and reaching the O2 sensor disconnects wasn't easy. 3 out of 4 of the exhaust manifold stud nuts came off no problem, but the 4th stud came off the manifold. I put it in a vice to get the nut off, but the stud wound up snapping in half. After running to 2 "pro" auto parts stores with no luck (one store claimed they had it, but their computer part # was wrong), I wound up finding the stud at Autozone by my house. I also had 2 trans crossmember bolts on each side snap off at the heads, but I think the 2 remaining on each side should hold it fine.d Got it all back together and it runs great again! I forgot how fast this truck really is!

BTW, even though I probably should have replaced the O2 sensors for good measure, they had been working fine and, at $50 apiece, I reused my old ones and no problems so far, KOW.

I also was able to look down the old Y pipe and was surprised that there was basically nothing in them--I could almost see right through them and could clearly see the holes I drilled. Apparently they had both completely collapsed and dumped into the rear 3rd converter (yes, it is a catalytic converter, not a resonator) which is intact. Thankfully nothing dumped through that 3rd converter because the back half of my exhaust and muffler is almost new and I didn't want to replace it again.

Thanks to everyone for their advice and assistance on all my issues!!

 

[SyberTiger]

Thanks for coming back and letting us know the final solution. Curious to know the likely failure of the cats? Just old or you have another problem that caused the cat failure?

 

[reansor]

Thanks for coming back and letting us know the final solution. Curious to know the likely failure of the cats? Just old or you have another problem that caused the cat failure?

Like another guy that replied to my previous posting on this thread comma I had to replace my intake manifold because I had the classic 4.6 L crack that was leaking coolant into spark plug well. I never saw any symptoms of it leaking into the cylinders, but who knows. Apparently cool and destroys catalytic converters, though, according to the other guys homework. I have a 2003 with 155000 miles, so who knows, maybe just age.

 

[Paulyy___g]

Here's an update for anyone in the future reading this... 2 months later and I still haven't replaced the cats lol. I know, I know but money is tight until work starts again in April. I had to drill a few more holes and used a 5/16 bit as I was having some pressure trouble that was making the engine barely able to get the truck past 40mph. Still sounds awful but not as bad as more air is escaping now I suppose. When the time comes I'm thinking I'll just get some universal cat converters and bolt them on, the whole y piece is pretty expensive and I'm fairly sure the universals will do the job.

 

[imp]

Here's an update for anyone in the future reading this... 2 months later and I still haven't replaced the cats lol. I know, I know but money is tight until work starts again in April. I had to drill a few more holes and used a 5/16 bit as I was having some pressure trouble that was making the engine barely able to get the truck past 40mph. Still sounds awful but not as bad as more air is escaping now I suppose. When the time comes I'm thinking I'll just get some universal cat converters and bolt them on, the whole y piece is pretty expensive and I'm fairly sure the universals will do the job.

@Paulyy___g
Damn! I was ready to bite the bullet, buy the "Y-pipe" with cats, and struggle through installing it. Hammered the R.H. cat, CEL went away, truck runs fine since, at least 3 months now. The hammering was done with eng. running 2500 rpm, held there by my wife. The repeating code, gone since the hammer job, was "HO2S Heater Resistance". imp