P0300

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Nov 3, 2019 | 10:15 AM

machete166

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CF Beginner

Joined: Nov 2019

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P0300

Hello all. Having issues with my 99 tahoe 4x4 2door v8 350. I'm having a P0300 code. cylinders 4,5,6, & 7 are misfiring. changed all spark plugs, spark plug wires, distributor cap and rotor, new coil, new ignition control module, new MAF, new O2 sensors, new Crankshaft position sensor, new fuel filter, and IAC. I have spark on all plugs. I get proper voltages in all areas. The only thing I can think of is the spider assembly has gone bad. it has the new MPFI system installed a few years ago. New Fuel pump was installed 1 year ago. Any ideas what can still cause this?

Nov 3, 2019 | 12:28 PM

mountainmanjoe

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Joined: Feb 2017

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You might get better answers from fellow owners in the Tahoe section. I would suggest testing the fuel injectors, and compression testing the misfiring cylinders.

Nov 5, 2019 | 5:03 AM

Ricardowelch

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Joined: Sep 2019

Posts: 15

Likes: 1

Quote:

Originally Posted by machete166

Hello all. Having issues with my 99 tahoe 4x4 2door v8 350. I'm having a P0300 code. cylinders 4,5,6, & 7 are misfiring. changed all spark plugs, spark plug wires, distributor cap and rotor, new coil, new ignition control module, new MAF, new O2 sensors, new Crankshaft position sensor, new fuel filter, and IAC. I have spark on all plugs. I get proper voltages in all areas. Visit Autofthings to review headlight clear coat if you concern. The only thing I can think of is the spider assembly has gone bad. it has the new MPFI system installed a few years ago. New Fuel pump was installed 1 year ago. Any ideas what can still cause this?

I think you should check all plug wires that are correct plug and tight.