Sputtering at High RPMS
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Joined: Aug 2023
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From: Salt lake city
Sputtering at High RPMS
I have a 2001 C5 with about 120,000 miles. It has this problem that I cannot figure out and it’s only intermittent and never lasts long enough to figure out what it is. When wide open on the throttle, at around 5000 RPM it will sputter before continuing to climb. I thought it to be the fuel filter and replaced it but to no help. The spark plugs and ignition wires were done less then a year ago, My air filter is clean to. Only some times when it does the sputtering it will flash a check engine light. The code ends up being P0300 with no specific cylinders being mentioned or no other codes. Any suggestions on what to try to see what could be causing this problem? I have also noticed that my exaust will shoot black liquid out of it. I thought it could be oil but it doesn’t smell like oil. It also doesn’t burn so i’m assuming it’s not gas. Could it just be condensation and it’s bringing all the soot out in the exaust with it?
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Joined: Sep 2013
Posts: 15,430
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From: Cape Coral, Florida
Do you have a scan tool or even a code reader to gather some data to see why your car is sputtering ??…without gathering some data you’ll only be guessing…it could be your O2 sensors, faulty or dirty MAF sensor, faulty MAP sensor, or a faulty cam or crank sensor.
Thread Starter
Advanced
Joined: Aug 2023
Posts: 56
Likes: 2
From: Salt lake city
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,430
Likes: 3,981
From: Cape Coral, Florida
Would be a little difficult to diagnose your car by just looking at screen shots…watch the 2 part video and see if you can understand the theory…look at your fuel trims and O2 sensors…at idle the upstream O2 sensors should oscillate between 200-800mv’s…the fuel trims should be + or - 10%….under load the upstream O2 sensors should go near 1 volt.
