DPFE issue

[RonSerling]

Ok I posted a question about cats on my 1999 Ranger 4.0 a while ago and got some great help. Now I have a question relating to the muffler as we replaced the cats and we are still experiencing the same problem. As I said we replaced all the cats on it but it still has a lot of back pressure and it is blowing the DPFE hoses off, and even caught one of them on fire the other day. My question is is it possible that the muffler is plugged and could that be the cause of this issue or has anyone had this issue before and if so what was done to fix it ??? As per usual any help and or answers would be a great help. Thanks

 

[Dirtman]

If your cats died and blew apart where do you think all that junk ends up? It gets stuck in the muffler...

 

[RonSerling]

If your cats died and blew apart where do you think all that junk ends up? It gets stuck in the muffler...

Well the front cat in the rear duo originally blew out the back was fine with no loss of internals. You could look from the back of the cat thru and see the materials in it were still in tact and upon emptying out the materials from the front one you could see light thru it wit a flashlight so the back one was still somewhat good !!

 

[Dirtman]

Have you hooked a vacuum guage to the engine and done a back pressure test? How are you figuring it's a back pressure issue? No judgement or insult intended, just asking.

Not sure what the "fire" is about. No fuel goes through the dpfe sensor. A broken hose just causes a vacuum leak... its literally just pressure from the intake to exhaust. No fire...

 

[85_Ranger4x4]

How old are the hoses?

When they get old they get hard and won't stay on. I went thru it on my F-150 roughly 5 years ago, any parts store should have replacement hose kits.

And they are special hose, fuel line may work in an emergency but it won't hold up to the heat (I tried)

 

[RonSerling]

Have you hooked a vacuum guage to the engine and done a back pressure test? How are you figuring it's a back pressure issue? No judgement or insult intended, just asking.

Not sure what the "fire" is about. No fuel goes through the dpfe sensor. A broken hose just causes a vacuum leak... its literally just pressure from the intake to exhaust. No fire...

Dirt, We used Caveman Mechanics tactics, LOL. First thing we did was disassemble the complete exhaust system. Then we put the Y pipe back on and started it up checking the amount of flow coming thru which was quite good. We also checked the flow at the dpfe ports on the EGR tube which was very slight. Next we attached the rear cats back into the system and did the same test. Flow there seemed really good also and the same at the dpfe being a slight amount of pressure there. Then we reconnected the muffler and restarted it again. This time when checking the flow at the muffler it seemed like it was a lot less and the pressure coming from the dpfe port seemed a lot higher. Now the one thing I am not sure of is what the actual pressure should be coming out that dpfe port but I can tell you it sure seemed to be flowing out there with a lot more volume and pressure. Caveman mechanics at its finest !! LOL

 

[RonSerling]

How old are the hoses?

When they get old they get hard and won't stay on. I went thru it on my F-150 roughly 5 years ago, any parts store should have replacement hose kits.

And they are special hose, fuel line may work in an emergency but it won't hold up to the heat (I tried)

Brand new hoses !! Yes !!

 

[Dirtman]

Everything you say points to clogged mufflers but. A vac guage costs less than 20 bucks at any parts store. That 20 dollar tool is the best diagnostic tool you can buy. It detects vacuum leaks, clogged exhaust, bad valves, even leaking heads. Even on the most sophisticated computer controlled engine a vac gauge is indispensable.

Hook it to a vacuum port on the manifold. Idle vacuum should be 20+hg. If you hit the throttle it should drop to near zero and snap back quick. Hold it open it should stay steady, if it builds up you have a clogged exhaust.

Get the guage...

 

[RonSerling]

Everything you say points to clogged mufflers but. A vac guage costs less than 20 bucks at any parts store. That 20 dollar tool is the best diagnostic tool you can buy. It detects vacuum leaks, clogged exhaust, bad valves, even leaking heads. Even on the most sophisticated computer controlled engine a vac gauge is indispensable.

Hook it to a vacuum port on the manifold. Idle vacuum should be 20+hg. If you hit the throttle it should drop to near zero and snap back quick. Hold it open it should stay steady, if it builds up you have a clogged exhaust.

Get the guage...

Just talked to my SnapOn dealer. He didnt have one on the truck but is gonna stop back tomorrow and bring me one !! 466.63 teaspoons ??? Thats a whole lot of teaspoons !! LOL

 

[Dirtman]

Buying a vac guage from a snap-on dealer... are you rich?

 

[RonSerling]

Buying a vac guage from a snap-on dealer... are you rich?

I been buying SnapOn for over 25 years. I got enough of their tools to start WWIII !!! And it is always a great tax write off !!

 

[Dirtman]

Hey... you do you... let us know what the results are of a full battery of vacuum guage tests.

 

[snoranger]

Buying a vac guage from a snap-on dealer... are you rich?

Snoranger quietly walks away and closes his Snap on filled tool box.

 

[alwaysFlOoReD]

alwaysFlOoReD looks out at his Snap-On tool box wishing it was full of Snap-On tools....

 

[Dirtman]

Dirtman proudly looks at his tool box full of stuff that pre dates snap-on's very existence...