Shortly after deleting my 2009 I added the Edge CTS2 Monitor. Mainly to watch the EGT when towing. I recently switched one monitor to Exhaust Back Pressure (EBP). When first switched at idle it would be zero. Now the idle is up to 2-3 lbs and at 70 mph (not towing) it runs 18-19. I remember it never got over about 10-12 unless I was towing and working the engine. It has been rising the last few weeks and makes me think the muffler is stopping up. I talked to a local shop that does mods and he said the factory muffler was straight thru and couldn't stop up. The fuel mileage has dropped slightly < 1mpg as best I can tell. Also the boost seems to be running higher when unloaded.

Any thoughts? Something is changing and not for the better. If anyone knows for sure if the muffler is straight thru I can eliminate it. Otherwise I will get the 4" muffler delete pipe (DPF back) and see what happens but I hate to spend $200+ if that's not the problem.

 

If it's not a testing state, the best things you can do to the truck is an EGR and DPF delete.

Read up. I just 6 months ago bought a beautiful replacement (someday) for my trusted and true 7.3 99Early. It sits in the garage, I've been funneling info on how and what makes it tick.

DPF is done. EGR is next. If you compare the two trucks, there is no comparison. The 7.3 has the new one hands down. However, like everything else there will be a time to move on.

If you can do these mods, get on it.

Denny

 

Thanks for the reply but I have already done the mods. I need to know the "normal" exhaust back pressure....

 

I am confused, If you deleted, the back pressure sensor should be disconnected?? And the tuning ignores it. Perhaps they are hanging there getting dirty??

 

The exhaust back pressure sensor is on the exhaust manifold. Not the ones on the cat/dpf setup.

 

Have you ever cleaned and or replaced your EBP and MAP sensors? EBP sensor will plug up with soot and cause erratic readings and boost fluctuations as well as poorer mileage. Map sensor can also clog up.

 

Neither have been cleaned. The boost pressure appears normal for my driving. It's just the EBP is higher than normal. It doesn't jump around or behave erratically, just high. What I'm seeing is about a 2-1 ratio EBP to Boost, 8 lbs boost gives 16 EBP.

I haven't looked but is the EBP sensor cleanable? Findable?

 

EBP sensor is located on the drivers side of engine...you'll see a tube coming from the rear of the exhaust manifold with the ebp sensor attached to this tube. Both tube and ebp sensor can plug with soot. Yes it's cleanable.....I think I used carb cleaner to do mine a few times now.
On another note.....Have you deleted your EGR coolers? Is it cold out when this happens? The ebp sensor and tube can freeze due to moisture build up in colder weather and cause higher boost.

 

The EGR coolers have not been removed. The tuner turns the valve off. I have gotten mixed answers as to the necessity of the block-off plate when the valve is turned off. I have heard the cooler can stop up (carbon) and be expensive to replace if needed to go back stock. Thoughts?

The weather has not been below freezing for several weeks now although we did have a spell of teens. Thinking about it that may have been when all this started.

What is considered "normal" and high EBP???

 

Does any one know the answer ?

 

is the CAT still installed? if you deleted the "clean the DPF" programing....what is cleaning the CAT? as soot builds up on the CAT, back pressure will increase. most DPF delete straight pipes connect to the CAT, so im thinking your problem is clogging CAT.

 

No cat . I cleaned the sensor and will report back but there is no taking the tube off living on salty roads makes the pipes paper thin.

 

Where is the MAP sensor?

 

Manifold Absolute Pressure (MAP) Sensor
graphic
Item Part Number Description
1 14A464 Manifold absolute pressure (MAP) sensor electrical connector (part of 12B637)
2 9F479 MAP sensor
Removal and Installation
CAUTION: Make sure the ignition switch is in the OFF position prior to working on the electronic engine controls or the vehicle may be damaged.
Turn the ignition switch to the OFF position.
Remove the air cleaner outlet tube. Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
Remove the MAP sensor.
To install, tighten to 12 Nm (106 lb-in).
To install, reverse the removal procedure.


Pic.

Looking from the grill, to the Left of the filters on the right engine bank. Tried to share a pic but no go.

Denny

 

Ah...I imagine it would be easier to take off the S&B intake tube to get to this. Thanks Denny. Fu(ing A man.