P0300 Code Can't figure it out
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P0300 Code Can't figure it out
So my car is throwing the dreaded P0300 code. Tried searching but nothing helped so far so trying this incase I missed something. Car is 99 Z28 with mods in sig... Sometimes when driving on the expressway around 3500-4000 rpms the ses would start flashing. If I shifted it would stop. Have a Snap-On MT2500 scanner and while using the misfire section every cylinder misfires. Sprayed for vacuum leaks, nothing. Occasionally at idle the rpms will jump from 800 to 1000rpm for a split second. Plug wires are good, and plugs are good. Rear o2's are deleted. Now the other o2 readings jump from 100-800 constantly. Could that mean both my o2's are bad. I'm going off the scanner. Sorry don't know much about using these scanners except for reading DTC's. I need to figure this out soon cause I have emissions due by the end of the month and I'm stumped!!!!
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I'll have to check that out later. I'm just starting to get into panic mode cause of emissions. It's not a dd so if it wasn't for emissions I wouldn't be rushing. That's why the 2 posts but I'm forgetting about the other one
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Unplug your mass air meter and try again. At the rpm you are having issues at is where the ecm starts to use the maf 100%.. So it may be a bad mass air meter causing a massive lean condition.
Unplug the sensor, and go for a drive. It will throw a light of coarse, but it will prove the point.
Unplug the sensor, and go for a drive. It will throw a light of coarse, but it will prove the point.
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So an update....Got the maf from my buddy only to learn that I don't believe I have a factory maf since mine is bigger than his unless they were different sizes from 99, which is mine, to 02 which is his. Also leading me to believe my throttle body is bigger also. It is a 3 wire maf so i'm so unsure. If anyone can help i'd appreciate it. I can add a pic of my maf if it helps. New alternator showed up today so I'll throw that in sometime this week.