Will an exhaust leak make your motor run rich?
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Joined: Oct 2005
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Will an exhaust leak make your motor run rich?
Will an exhaust leak after the o2 sensor make your motor run rich? If so why is that?
I am running:
Hondata s200b
RC 750cc injectors
Walbro HP intank 255lph fuel pump
My car has been tuned and running perfect for over a year. Just since last night is when I started noticing a problem.
My idle is normally at 1000-1100 rpm set by the Hondata, but just recently it has dipped down into the 500s and surges up and down. On top of that, I am running extremely rich. The smell of gasoline and black smoke is coming from the tailpipe(which never happened before). Also, I've noticed my greddy EGT guage has read lower than normal when I am driving around on the highway. Normally, my EGTs are around 600 degrees celcius while cruising at around 3000rpm, but recently my EGTs have dipped down to 450-500 degrees celcius. The car also feels a little more sluggish while cruising, a very very slight hesitation can be felt as well. So something is definitely not right. Could it be anything else?
I've already checked my spark plugs, and each and every single plug is pitch black which is not right. Normally they are grey at the tip and black around the ring.
I also pulled my fuel pump to check everything was ok there, and it was.
Any help/ideas are greatly appreciated! Thanks in advance.
Khoi
I am running:
Hondata s200b
RC 750cc injectors
Walbro HP intank 255lph fuel pump
My car has been tuned and running perfect for over a year. Just since last night is when I started noticing a problem.
My idle is normally at 1000-1100 rpm set by the Hondata, but just recently it has dipped down into the 500s and surges up and down. On top of that, I am running extremely rich. The smell of gasoline and black smoke is coming from the tailpipe(which never happened before). Also, I've noticed my greddy EGT guage has read lower than normal when I am driving around on the highway. Normally, my EGTs are around 600 degrees celcius while cruising at around 3000rpm, but recently my EGTs have dipped down to 450-500 degrees celcius. The car also feels a little more sluggish while cruising, a very very slight hesitation can be felt as well. So something is definitely not right. Could it be anything else?
I've already checked my spark plugs, and each and every single plug is pitch black which is not right. Normally they are grey at the tip and black around the ring.
I also pulled my fuel pump to check everything was ok there, and it was.
Any help/ideas are greatly appreciated! Thanks in advance.
Khoi
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Joined: Dec 2004
Posts: 672
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Originally Posted by sohc driver
Will an exhaust leak after the o2 sensor make your motor run rich? If so why is that?
I am running:
Hondata s200b
RC 750cc injectors
Walbro HP intank 255lph fuel pump
My car has been tuned and running perfect for over a year. Just since last night is when I started noticing a problem.
My idle is normally at 1000-1100 rpm set by the Hondata, but just recently it has dipped down into the 500s and surges up and down. On top of that, I am running extremely rich. The smell of gasoline and black smoke is coming from the tailpipe(which never happened before). Also, I've noticed my greddy EGT guage has read lower than normal when I am driving around on the highway. Normally, my EGTs are around 600 degrees celcius while cruising at around 3000rpm, but recently my EGTs have dipped down to 450-500 degrees celcius. The car also feels a little more sluggish while cruising, a very very slight hesitation can be felt as well. So something is definitely not right. Could it be anything else?
I've already checked my spark plugs, and each and every single plug is pitch black which is not right. Normally they are grey at the tip and black around the ring.
I also pulled my fuel pump to check everything was ok there, and it was.
Any help/ideas are greatly appreciated! Thanks in advance.
Khoi
I am running:
Hondata s200b
RC 750cc injectors
Walbro HP intank 255lph fuel pump
My car has been tuned and running perfect for over a year. Just since last night is when I started noticing a problem.
My idle is normally at 1000-1100 rpm set by the Hondata, but just recently it has dipped down into the 500s and surges up and down. On top of that, I am running extremely rich. The smell of gasoline and black smoke is coming from the tailpipe(which never happened before). Also, I've noticed my greddy EGT guage has read lower than normal when I am driving around on the highway. Normally, my EGTs are around 600 degrees celcius while cruising at around 3000rpm, but recently my EGTs have dipped down to 450-500 degrees celcius. The car also feels a little more sluggish while cruising, a very very slight hesitation can be felt as well. So something is definitely not right. Could it be anything else?
I've already checked my spark plugs, and each and every single plug is pitch black which is not right. Normally they are grey at the tip and black around the ring.
I also pulled my fuel pump to check everything was ok there, and it was.
Any help/ideas are greatly appreciated! Thanks in advance.
Khoi
I commend you on doing your homework and knowing the basics...
It does sound as though your engine is running excessivly rich. Lower egt's could be because of an excessive rich condition and a loss of power is an indication. Sounds like you check your plugs often, so I would lean towards possibly the 02 sensor giving up.. Although it should throw a code, your afr and agt's would be all aout of whack with a bad 02.
Thread Starter
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Joined: Oct 2005
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Originally Posted by b16ahybrid
I commend you on doing your homework and knowing the basics...
It does sound as though your engine is running excessivly rich. Lower egt's could be because of an excessive rich condition and a loss of power is an indication. Sounds like you check your plugs often, so I would lean towards possibly the 02 sensor giving up.. Although it should throw a code, your afr and agt's would be all aout of whack with a bad 02.
It does sound as though your engine is running excessivly rich. Lower egt's could be because of an excessive rich condition and a loss of power is an indication. Sounds like you check your plugs often, so I would lean towards possibly the 02 sensor giving up.. Although it should throw a code, your afr and agt's would be all aout of whack with a bad 02.
Khoi
Senior Member
Joined: Jan 2003
Posts: 1,994
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The exhaust leak might just cause it... IF(?) the exhaust swirls around under the car & collects up around the O2 sensor.
The O2 sensor really measures O2 difference from inside vs. outside. So if the air outside the sensor is full of exhaust, that's gonna create the same signal as a lean mixture; your ECU will try to compensate.
The O2 sensor really measures O2 difference from inside vs. outside. So if the air outside the sensor is full of exhaust, that's gonna create the same signal as a lean mixture; your ECU will try to compensate.
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The O2 sensor doesnt work that way. It is reactive to the amount of air a fuel in the exhaust. thats it. it will operate in total vacuum out side of the exhaust.
If there is an exhaust leak before the turbo the turbo will not move the same amount of air the car was tuned for.since Hondas use a MAP sensor instead of a MAF. The ECU can measure the pressure but not the actual flow or weight of the air going in the engine.
If there is an exhaust leak before the turbo the turbo will not move the same amount of air the car was tuned for.since Hondas use a MAP sensor instead of a MAF. The ECU can measure the pressure but not the actual flow or weight of the air going in the engine.