Hi,

I get this once in a while and it triggers my light....no change in performance at all and sometimes it will go a week without tripping the CEL.

I am wondering if there is any way to check this sensor (I believe it is right by the t/stat housing) or if there is just any opinions on just replacing it. Not sure what would cause this so I turn to you guys for help....as always thank you for the help


Joe

 

you need to check the pis of the sensor should be with in .5psi of map and baro key on engine off

 

If you could kinda dumb it up for me (pis?) that would be cool....I am not sure how to even begin to check what you are talking about.

Thanks Cheezit
Joe

 

sorry.you will need a scantool that can moniter pid values. basicly you need to know what the pcm is seeing

 

I don't know "pis" but I DO know about ****. It's what I do very often when I have a few too many to drink. As far as checking it, if it's dark yellow, it means you're not drinking enough. If it's clear as water, it means you're drinking too much.

On a more serious note, what cheezit is referring to, is your MAP (Manifold Absolute Pressure), BARO (Barometric Pressure) and EBP (Exhaust Back Pressure) readings at key-on/engine-off. The readings for the three sensors are in PSI (Pounds Per Square Inch) units. By virtue of the fact that the engine is not running when checking the readings with the key in the RUN position, all three sensors should have equal readings (about 14.3 psi). When the engine is started, MAP and EBP should increase slightly. If EBP is reading let's say 15 to 16 psi, while MAP and BARO are at 14.5, then the EBP sensor needs to replaced. Similarly, if you see MAP and BARO at 14.5 and EBP is at 12 or 13. Are you hearing any turbo fluttering? Usually when EBP readings are off, you'll hear a turbo flutter after you release the throttle when accelerating. To monitor the three data listed, you'll need a scan tool that is capable of reading live data.

 

sorry man fat fingured the key board again. lmao. the D is to close to the S

 

Aaaaahhh yes, I gotcha. You meant to type PID (Parameter Identification Data) not PSI (Pounds Per Square Inch). I had thought you reversed the "i" and the "s" by mistake. Thanks for clearing that up.

 

hahaha I figured as much. I bet I know what the problem is.....my quadzilla monitor had me splice a 24 gauge wire into the MAP sensor for a boost reading. I removed that wire today since I installed a mechanical boost that proved what I have been thinking all while long...the quadzilla was wrong. My boost NEVER went above 19psi even tuned....now I am normal ranged since the mechanical install.


Since you guys mentioned the MAP and BARO work together with the EBP sensor, it all kinda makes sense that the extra wire I spliced into the MAP sensor was interrupting the signal.

I will monitor it further....since I dont have a scantool and it continues...I'll just change the EBP sensor.

Cheezit or mchan68....do you guys have a part number for a 2004 (Nov 2003 build) 6.0L engine back pressure sensor?

Thanks for the help


COINCIDENTALLY.....what do you guys think of my idea for the problem in relation to the spliced wire for boost signal?

 

4C3Z-9J460-A or DPFE-3


Are you getting a P0470 by itself or in conjunction with other DTCs? Usually P0470 sets if the PCM doesn't see and EBP reading it likes.

 

The only DTC I get is the P0470.....I'll clear it and it comes back under no particular circumstance (ie full throttle, coast, constant RPM etc) . I was wondering Mchan68.....there is a rigid line that screws to the bottom of the EBP....not sure what it is, but can only assume it is a line routed from the exhaust? How does the EBP get its reference reading?


....and am I correct on its location.....right by the thermostat?

....and what exactly does the EBP do?

Thanks
Joe

 

Yes, on a 2004 model year, the EBP sensor is mounted on a bracket that is bolted over top of the thermostat housing, which is in turn secured to a hollow steel line connected to the driver side exhaust manifold. If you do replace the sensor, be sure to clean the soot build up inside the line too. The EBP sensor monitors exhaust back pressure, hence its name to provide an input to the PCM as to the appropriate level of turbo boost needed to achieve the desired engine output, based on driver input (accelerator pedal position).

 

You are the man.........thank you buddy....rep points for certain. I will check it soon.

Thanks for the help
Joe

CR*P...it wont let me....I'll get you soon

 

Mchan68,

I have a question for you....If I understand it correctly all of the backpressure is created by the turbo and some from the CAT/Muffler. Since the hollow tube for the EBP sensor references BP from the drive side exhaust manifold, is it possible that my EBP is having issues because I have a straight piped 4" exhaust?

 

back pressure comes from the vgt, the egr valve and the cat muffler. you may see a drop in mgp as a result of modifing any of the above.

 

ok....so do you think that by modifying either of the four (as I removed three of the four but had a tune written to remove the EGR strategy) would give me a faulty reading at the EBP and trigger the CEL?