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Discussion Starter · #1 ·
ok well im going to tackle all my codes tomorrow as im getting geared up for the drive to florida in the mustang

ive got 3 codes.


#1


the one im most worried about is this one

OBD-II Trouble Code: P0402 Exhaust Gas Recirculation (EGR) Flow Excessive Detected



ive been doing ALOT of research and i think that i need a new DPFE sensor

i did a little testing while i was at work on break and i unplugged some vac lines.... nothing happened

i unplugged some electrical connectors... nothing happened

but when i took a vacuum line that was pulling a little and plugged it to the top of the egr valve the car bogged down and almost died... so does this mean my egr is functioning? this is what brought me to believe that its the DPFE sensor

#2 & 3

OBD-II Trouble Code: P0131 Oxygen O2 Sensor Low Voltage (Bank1, Sensor1)

OBD Trouble Code: P1151 Lack of HO2S-21 Switch, Sensor Indicates Lean

these are pertaining to my 02 sensors and i think i need to replace them
BUT heres the catch..... i (to my knowledge) have an exhaust leak. im taking it to a muffler shop tomorrow to see if its a donut gasket or if its a cracked manifold.

i was thinking it was the manifold so i ALMOST bought headers like i was one click away from "confirm payment" lol and then i thought hmmm i should get a shop to look at it.

also i seafoamed it like last month but only in the intake... is it ok to do it again to find the leak??

back to the codes... if i get this mysterious leak fixed and the codes dont go away should i replace the sensors?

or should i replace the sensor anyways

it also seems like the codes may have to do with the first code??? idk any light shedd would be much appreciated

EDIT: no i am not deleting the EGR yet i want to wait till i have a tuner :D
 

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Just Cheesin'
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Don't just change parts expecting the codes to go away..
 

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Discussion Starter · #3 ·
Don't just change parts expecting the codes to go away..
hmmmm isnt that what you do though? i mean code pops up, you go get the part to fix it... code goes away :confused:

i sort of understand but if there is a faulty part then replacing it should get rid of the problem therefore relieving the CEL

im like 98% positive its the DPFE sensor

and i didnt mention that idle is shaky a little and at very slight throttle around 1200-1500 rpms its shaky.

really the only things im worried about is making sure the egr system is functioning again untill i delete it, so that the car runs good for the 14 hour trip and im a little concerned about the 02 sensors because i dont want to end up with clogged cadillac:eek: converters haha jk... catalytic :cool:
 

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Just Cheesin'
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Just because a code came up relevant to a part, doesn't mean the part it bad. The part could be working fine, but showing faulty parameters.

Like the First o2 code.. Says low voltage. It could be that the reference voltage is low enough to set a code using the reference, but not low enough to set a low reference code.
 

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Discussion Starter · #5 ·
Just because a code came up relevant to a part, doesn't mean the part it bad. The part could be working fine, but showing faulty parameters.

Like the First o2 code.. Says low voltage. It could be that the reference voltage is low enough to set a code using the reference, but not low enough to set a low reference code.
OHHHH yeah ok im starting to get on the same page here... what your saying is because the bank 1 sensor one is throwing a code... maybe the sensor is fine but SOMETHING that is incorrect ( exhaust leak, short in wiring etc. ) most likely is causing it to send the computer a bad signal.
 

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One month ago I had the same first two codes caused by a bad upstream O2 sensor. I had my brother n law verify m~volts sending unit and it ended up correcting my lean mixture and egr problems. I really can not remember the test procedure though, sorry.
 

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Discussion Starter · #7 ·
One month ago I had the same first two codes caused by a bad upstream O2 sensor. I had my brother n law verify m~volts sending unit and it ended up correcting my lean mixture and egr problems. I really can not remember the test procedure though, sorry.
was it just one 02 sensor that you replaced? and it corrected the egr problems....
i hate that there are so many variables :mad:
 

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Just Cheesin'
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Just because that worked for him doesn't mean it will for you. But in the end, do what you feel is necessary. (I would get a diagnostic key for those codes) but I doubt you have access to shopkey.
 

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Discussion Starter · #9 ·
Ok I went to the shop and the muffler guy was pretty knowledgeable... he said I need a new manifold because it is cracked rigght above the flange so I went to autozone and got my codes checked again. Only two codes now the dpfe sensor one and the 02 sensor one pertaining to bank 1 sensor 1 so I'm going to get a new manifold... their $100 at autozone with lifetime warranty but I'm going to check online and such. I. Also picked up ccarb cleaner to see if I can clean out that sensor, clean out the vac lines etc.

Am I on the right path herre guys???

Also does anyone have a stock exhaust manifold for the passenger side they would sell me??? :D
 

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You can get the manifold welded. That's what I did when I had a crack in my driver side exhaust manifold :dunno
 

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Discussion Starter · #11 ·
I asked the shop if they would weld it up and he said no? Where could I go... there's no like mom and pop shops around here but I have one I could check. How much did you pay so I know if I'm getting ripped. I would rather do that because I'm getting longtubes as soon as I get to florida.

Does anyone know a good procedure to clean out my dpfe sensor. I can't really find anything with the search button
 
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