Wife has been complaining of rare instances of the engine stumbling and sometimes dying in an '02 Avalon w/133k mi.
Scanned the engine and found no codes. Finally yesterday I drove it and felt the stumble, feathered the accelerator and was able to get a CEL. Codes came up P0300 (multiple misfire) and P0304 and P0306 (misfire cylinder specific). Cleared the codes and drove it for 50 miles with no issues. The engine runs really well normally, starts flawlessly, and idles right. Seems like the stumbling occurs 2 to 3 miles from dead cold, and doesn't occur once the engine is fully warmed.
I'm thinking of a coil or plug shorting just as the open/closed loop voltage changes. Any thoughts?
Scanned the engine and found no codes. Finally yesterday I drove it and felt the stumble, feathered the accelerator and was able to get a CEL. Codes came up P0300 (multiple misfire) and P0304 and P0306 (misfire cylinder specific). Cleared the codes and drove it for 50 miles with no issues. The engine runs really well normally, starts flawlessly, and idles right. Seems like the stumbling occurs 2 to 3 miles from dead cold, and doesn't occur once the engine is fully warmed.
I'm thinking of a coil or plug shorting just as the open/closed loop voltage changes. Any thoughts?
Last edited: