revs when lifting off accelerator pedal
#1
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revs when lifting off accelerator pedal
2007 Pontiac Grand Prix NA 3.8
as the title says, the engine revs when lifting off accelerator pedal as I drive. is this a common issue? is there a common place where a vacuum leak forms on this engine?
incidentally, it does have a code for the downstream O2 sensor, but i assumed that isn't something that would affect the air fuel mixture in this way, or was GM so uptight about emissions and fuel efficiency that they lean out your ratio if the post cat sensor doesn't pickup any O2?
as the title says, the engine revs when lifting off accelerator pedal as I drive. is this a common issue? is there a common place where a vacuum leak forms on this engine?
incidentally, it does have a code for the downstream O2 sensor, but i assumed that isn't something that would affect the air fuel mixture in this way, or was GM so uptight about emissions and fuel efficiency that they lean out your ratio if the post cat sensor doesn't pickup any O2?
#2
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Does it seem like it almost wants to stall out before it starts catching itself with the revving?
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2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
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2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
#3
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#4
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No other codes listed?
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2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
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2023 Jeep Rubicon Diesel
#5
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#6
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You could try and spray brake clean around the top of the engine while its running to check for vacuum leaks, but aside from that, its hard to say what is causing this without some sort of hard fault, or live data from a good scanner.
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2002 *-10 5.7 V8
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#7
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I have a Bluedriver and it has live data. what should I be looking at?
#8
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How much does it rev?
. . . like you're driving along at 2,000RPM and you let your foot off the pedal and it goes to . . .
. . . 2,100RPM?
. . . 2,008RPM?
. . . 5,000RPM?
No, the PCM reverts to pre-mapped values so as to put a good effort into saving your catalytic converter from damage but not do such a good job of conserving fuel and maximizing emissions reductions.
. . . like you're driving along at 2,000RPM and you let your foot off the pedal and it goes to . . .
. . . 2,100RPM?
. . . 2,008RPM?
. . . 5,000RPM?
No, the PCM reverts to pre-mapped values so as to put a good effort into saving your catalytic converter from damage but not do such a good job of conserving fuel and maximizing emissions reductions.
#9
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ok, i tried that with spray carb cleaner and detected no change in RPM.
#10
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hmm.