gutted cats, now the motor is pinging?
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: gutted cats, now the motor is pinging? Rear O2s have nothing to do with it. That much I can tell you.
An exhaust leak would cause you to run rich due to the Ltrims falsely going way positive. This would not induce pinging.
If anything, getting rid of the cats should lessen pinging.
I would suggest Autotapping. Check the Ltrims and O2 readings.
An exhaust leak would cause you to run rich due to the Ltrims falsely going way positive. This would not induce pinging.
If anything, getting rid of the cats should lessen pinging.
I would suggest Autotapping. Check the Ltrims and O2 readings.
Re: gutted cats, now the motor is pinging? Exhaust back pressure has always
been the "poor man's EGR". More
spent charge remains in the cylinder,
less fresh charge is inhaled, the
result is a diluted cylinder charge
and reduced peak cylinder pressure.
A control loop tuned for backpressure
with aggressive advance and lean mix
may get by, until you grossly improve
the exhaust flow. Then the -consequences-
of a naturally lean mixture are magnified.
Has it been given a chance to learn the
error of its ways?
been the "poor man's EGR". More
spent charge remains in the cylinder,
less fresh charge is inhaled, the
result is a diluted cylinder charge
and reduced peak cylinder pressure.
A control loop tuned for backpressure
with aggressive advance and lean mix
may get by, until you grossly improve
the exhaust flow. Then the -consequences-
of a naturally lean mixture are magnified.
Has it been given a chance to learn the
error of its ways?
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 140
Likes: 0
From: NOLA
Re: gutted cats, now the motor is pinging? no i drove it and it was fine for about 10 mins. then all hell broke loose and it lost power and started making noise. should i reset the computer?
btw: 98 t/a a4 lid,LM,descreened maf
<small>[ November 27, 2002, 09:34 PM: Message edited by: fatboy ]</small>
btw: 98 t/a a4 lid,LM,descreened maf
<small>[ November 27, 2002, 09:34 PM: Message edited by: fatboy ]</small>
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Re: gutted cats, now the motor is pinging? All hell broke loose and it started loosing power? By that description it sounds like you may have more important problems than simple pinging.
Any knocking going on at idle?
Do you have access to Autotap?
Jimmyblue, I understand what you're saying there and I would agree that gutting cats should increase pinging...except, it's been mine and others experience to the contrary. Jayson at MTI, for example, told me that quite often they get rid of knock retard by simply getting rid of the cats. I too noticed this when I gutted the cats on my '00. Go figure?
Any knocking going on at idle?
Do you have access to Autotap?
Jimmyblue, I understand what you're saying there and I would agree that gutting cats should increase pinging...except, it's been mine and others experience to the contrary. Jayson at MTI, for example, told me that quite often they get rid of knock retard by simply getting rid of the cats. I too noticed this when I gutted the cats on my '00. Go figure?
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 140
Likes: 0
From: NOLA
Re: gutted cats, now the motor is pinging? i wanted to update this for yall. what i thought was pinging was in fact a nasty *** exhaust leak from the sleeve i used to patch up the cut i made in front of the passenger side cat. it was leaking and then apparently(sp?) slipped becoming worse. i have since had it welded and all is well. that's what i get for cutting corners i guess, anyways the car feels a little better on topend interstate and is louder than before but the drone from the LM is gone at cruise (i have an a4) and it sounds like nasty *** on acceleration and gear shift
LM+gutted cats= <img border="0" alt="[barf]" title="" src="graemlins/gr_barf.gif" />
LM+gutted cats= <img border="0" alt="[barf]" title="" src="graemlins/gr_barf.gif" />
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