Please help with misfire
Thread Starter
4th Gear
Joined: May 2024
Posts: 4
Likes: 0
Please help with misfire
Hi please I need help with my 2009 Corvette
I have check engine light sometimes flash and traction light on. Check it with scanner I have misfire p0300 and the car only misfire on idle higher rpm nothing even check engine goes , I changed wire, plugs, all the injectors clean it at shop with machine changed MAP SENSOR still the same and the data on scanner shows 4 and 6 misfiring so so I removed The head and checked the valve all good and changed head gasket but the same nothing change so I checked the piston pressure all 180 except cylinder 4 and 6 150 psi could be the piston rings.also checked all wire good
Please if someone can help I appreciate
I have check engine light sometimes flash and traction light on. Check it with scanner I have misfire p0300 and the car only misfire on idle higher rpm nothing even check engine goes , I changed wire, plugs, all the injectors clean it at shop with machine changed MAP SENSOR still the same and the data on scanner shows 4 and 6 misfiring so so I removed The head and checked the valve all good and changed head gasket but the same nothing change so I checked the piston pressure all 180 except cylinder 4 and 6 150 psi could be the piston rings.also checked all wire good
Please if someone can help I appreciate
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,561
Likes: 4,033
From: Cape Coral, Florida
Even if you changed all those parts you should still check the electrical side of the coil packs (4 wires) and injectors (2 wires)…not knowing your electrical expertise I’ll stop right here…usually idle only misfires are ignition related…why was MAP sensor changed for a misfire ????
Last edited by C5 Diag; May 15, 2024 at 05:32 PM.
Thread Starter
4th Gear
Joined: May 2024
Posts: 4
Likes: 0
I changed a the map sensor because when I unplugged it's run fine and no misfire and no traction control light.i swap the coil and the injectors and checked all the wire 4 for the coil and 2 for the injectors and the same side of the misfire the catalytic converter was broken I removed pieces.
Really thanks
Really thanks
Drifting
Joined: Apr 2016
Posts: 1,286
Likes: 611
From: DFW Texas
One other possibility not mentioned is a failing torque tube bearing or rubber coupler. These can send vibrations to the engine that are interpreted as a misfire by the ECU. Are you having or feeling any noises or vibrations that seem located in the middle of the car when driving? That would be something to have checked out to eliminate the possibility.
Good luck...GD
Good luck...GD
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