EGR block off plate = strong exhaust stink with a twist
02-20-2014, 03:20 PM
#1
Launching!
Thread Starter
EGR block off plate = strong exhaust stink with a twist So, I recently installed a block off plate/gasket on
my EGR fitting (pacesetter long tubes with provisions.)
My EGR valve was previously still in the engine bay, but
blocked off using a ghetto pop can make shift plate.
It was still plugged in and would throw a low efficiency
code frequently.
This was done because I upgraded my 98 to an LS6
intake manifold.
Since I've installed the proper block off plate I've noticed
that my exhaust STINKS..like eye burning bad. And I'm
used to the normal no cats longtube smell. Does this
make any sense? As I say, the EGR valve wasn't doing
anything before as it was blocked off but still plugged
in. Just don't see why it would get all stinky now!
my EGR fitting (pacesetter long tubes with provisions.)
My EGR valve was previously still in the engine bay, but
blocked off using a ghetto pop can make shift plate.
It was still plugged in and would throw a low efficiency
code frequently.
This was done because I upgraded my 98 to an LS6
intake manifold.
Since I've installed the proper block off plate I've noticed
that my exhaust STINKS..like eye burning bad. And I'm
used to the normal no cats longtube smell. Does this
make any sense? As I say, the EGR valve wasn't doing
anything before as it was blocked off but still plugged
in. Just don't see why it would get all stinky now!
02-20-2014, 03:56 PM
#2
On The Tree
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Did you tune out the egr when you removed it? If not, that is why. Mine is doing the same thing...egr was removed and the exhaust smells rich and it hasnt been tuned.
Have it tuned, problem solved.
Have it tuned, problem solved.
02-21-2014, 08:58 AM
#3
Launching!
Thread Starter
^No not yet..gotta wait till the snow stops flying! I just find
it odd that it wouldn't stink before I did this as it was non
functional (not plugged into intake manifold due to LS6
upgrade.)
Thanks!
it odd that it wouldn't stink before I did this as it was non
functional (not plugged into intake manifold due to LS6
upgrade.)
Thanks!
03-08-2014, 03:35 PM
#4
Launching!
Thread Starter
Is it considered normal for a lot of popping (back firing) to
occur through the exhaust after an egr delete? (pre tune.)
It hasn't thrown any codes besides P0 405.Sounds like a step/anti lag at low
rpms if I floor it "pop pop pop!" Hasn't affected performance. Sounds like a
gun shot though.
occur through the exhaust after an egr delete? (pre tune.)
It hasn't thrown any codes besides P0 405.Sounds like a step/anti lag at low
rpms if I floor it "pop pop pop!" Hasn't affected performance. Sounds like a
gun shot though.
03-08-2014, 08:31 PM
#6
Launching!
Thread Starter
Yeah I'm not on the stock tune. I did have it dyno tuned after I installed the lid, longtubes & ory. All that I've added since then is the ls6 intake, potz tb and egr delete. I was under the impression that those are minor mods that might amount to 15 rwhp tops. fuel economy and driveability hasn't changed for the worse. You're right though, I will get my tune touched up once my dyno guy reopens for spring.
03-08-2014, 08:40 PM
#7
Launching!
Thread Starter
I guess my question is: how normal is the egr delete exhaust popping pre tune and is it going to cause damage driving in the meantime? Not that I have much of a choice haha
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03-09-2014, 11:26 AM
#8
TECH Apprentice
I've had a few newer vehicles with no cats, egr, air etc etc... And non of them ever popped or crackled because of the removal of those things.
Sure, you get the rasp, crackle, popping sound from a ory with certain mufflers, but not like what you're describing.
Sure, you get the rasp, crackle, popping sound from a ory with certain mufflers, but not like what you're describing.
03-09-2014, 04:37 PM
#9
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When EGR is (believed) active the PCM adds spark to
make up for the punked cylinder charge. Excess spark
and lean mixture makes NOx which is what burns your
eyes; lean misfire also makes the hydrocarbons come
up, which people misinterpret as being rich. I'd turn off
the EGR stuff, people say if you just disable the main
then you don't have to zero the EGR adder table.
make up for the punked cylinder charge. Excess spark
and lean mixture makes NOx which is what burns your
eyes; lean misfire also makes the hydrocarbons come
up, which people misinterpret as being rich. I'd turn off
the EGR stuff, people say if you just disable the main
then you don't have to zero the EGR adder table.
03-10-2014, 10:03 AM
#10
Launching!
Thread Starter
is handy for clearing out the left lane. It's only at low rpms,
the tach still climbs as smooth as ever and it sound like
it's coming out of the muffler area, not the engine
thankfully! Still, I'm looking forward to a retune when
winter is officially over.
03-10-2014, 10:06 AM
#11
Launching!
Thread Starter
When EGR is (believed) active the PCM adds spark to make up for the punked cylinder charge. Excess spark
and lean mixture makes NOx which is what burns your
eyes; lean misfire also makes the hydrocarbons come
up, which people misinterpret as being rich. I'd turn off
the EGR stuff, people say if you just disable the main
then you don't have to zero the EGR adder table.
and lean mixture makes NOx which is what burns your
eyes; lean misfire also makes the hydrocarbons come
up, which people misinterpret as being rich. I'd turn off
the EGR stuff, people say if you just disable the main
then you don't have to zero the EGR adder table.
programming? Thanks for your detailed post. That kind of
info is very helpful! Am I possibly risking nuking my spark
plugs in the mean time/burning a valve?
Like I say though, luckily the only code that's come up
(besides the stupid longtube perpetual O2 slow response
code..) is P0 405 (egr non functional.) It has never thrown
a lean or misfire code.
03-10-2014, 11:26 AM
#12
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Misfire detection works on crank-jerk (ripple) and will
pick out one cylinder or a couple that stand out from
the rest. But if all are put equally lean the firing event
will be equally "mis" and no detection can be made by
the PCM's limited algorithm-intelligence. The firing is
regular, but nonideal for the ingredient mix, and the
flame chemistry is off target.
This chart is for simple AFR at ideal timing; adding EGR
dilution and now-nonideal timing adds another dimension
to the mix (heh).
pick out one cylinder or a couple that stand out from
the rest. But if all are put equally lean the firing event
will be equally "mis" and no detection can be made by
the PCM's limited algorithm-intelligence. The firing is
regular, but nonideal for the ingredient mix, and the
flame chemistry is off target.
This chart is for simple AFR at ideal timing; adding EGR
dilution and now-nonideal timing adds another dimension
to the mix (heh).
03-10-2014, 11:33 AM
#13
Launching!
Thread Starter
Misfire detection works on crank-jerk (ripple) and will
pick out one cylinder or a couple that stand out from
the rest. But if all are put equally lean the firing event
will be equally "mis" and no detection can be made by
the PCM's limited algorithm-intelligence. The firing is
regular, but nonideal for the ingredient mix, and the
flame chemistry is off target.
This chart is for simple AFR at ideal timing; adding EGR
dilution and now-nonideal timing adds another dimension
to the mix (heh).
pick out one cylinder or a couple that stand out from
the rest. But if all are put equally lean the firing event
will be equally "mis" and no detection can be made by
the PCM's limited algorithm-intelligence. The firing is
regular, but nonideal for the ingredient mix, and the
flame chemistry is off target.
This chart is for simple AFR at ideal timing; adding EGR
dilution and now-nonideal timing adds another dimension
to the mix (heh).
that to my tuner or will it be painfully obvious when he's
plugged in and loading it on the dyno?
Thanks again, your posts are of tremendous help.
03-10-2014, 04:20 PM
#14
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On the dyno, you are out of EGR-active operation.
EGR is for low cruise emissions and a little economy
bonus, should be inactive by the time you hit PE.
Now, any positive fuel trimming error caused by the
EGR situation would bother WOT tuning. I'd keep an
eye on the LTFTs when you get on the rollers, better
yet zero them before pulling any data and then work
on making sure they stay zero or slightly negative.
But you may, or may not see positive trims now. A
state of tune that makes a lot of NOx, though, I'd
suspect to trim positive since NOx comes most from
lean-in-the-hole (and overadvanced).
EGR is for low cruise emissions and a little economy
bonus, should be inactive by the time you hit PE.
Now, any positive fuel trimming error caused by the
EGR situation would bother WOT tuning. I'd keep an
eye on the LTFTs when you get on the rollers, better
yet zero them before pulling any data and then work
on making sure they stay zero or slightly negative.
But you may, or may not see positive trims now. A
state of tune that makes a lot of NOx, though, I'd
suspect to trim positive since NOx comes most from
lean-in-the-hole (and overadvanced).
03-10-2014, 04:53 PM
#15
Launching!
Thread Starter
On the dyno, you are out of EGR-active operation.
EGR is for low cruise emissions and a little economy
bonus, should be inactive by the time you hit PE.
Now, any positive fuel trimming error caused by the
EGR situation would bother WOT tuning. I'd keep an
eye on the LTFTs when you get on the rollers, better
yet zero them before pulling any data and then work
on making sure they stay zero or slightly negative.
But you may, or may not see positive trims now. A
state of tune that makes a lot of NOx, though, I'd
suspect to trim positive since NOx comes most from
lean-in-the-hole (and overadvanced).
EGR is for low cruise emissions and a little economy
bonus, should be inactive by the time you hit PE.
Now, any positive fuel trimming error caused by the
EGR situation would bother WOT tuning. I'd keep an
eye on the LTFTs when you get on the rollers, better
yet zero them before pulling any data and then work
on making sure they stay zero or slightly negative.
But you may, or may not see positive trims now. A
state of tune that makes a lot of NOx, though, I'd
suspect to trim positive since NOx comes most from
lean-in-the-hole (and overadvanced).
your insight! I'll pass it along to my tuner.
