Q: Car has been misfiring since fixing the exhaust leak but now keeps dying after 10 mins

asked by on June 25, 2017

Recently replaced my flex pipe due to exhaust leak, now car keeps misfiring while driving. It happens after about 10 mins of driving. I can feel the accelerating having slight trouble going up gear, thought because it was running lean previously. I had 'your mechanic 'diagnosed my misfire and was told just replace the spark plugs. Replaced them and didn't seem to change anything. Also within this year also replaced camshaft sensor, ignition switch. Old codes include: p0171, p0113, p0139, p0350 Current code: p0300 Anything helps, it's stuck and needs towed, thanks.

My car has 203330 miles.
My car has an automatic transmission.

Hi there. If more than one cylinder misfires, this will increase or decrease the revolutions per minute (RPM) of the crankshaft. If that increase and/or decrease is more than 2 percent, the Powertrain Control Module will store the P0300 trouble code. This trouble code is a generic code that indicates a random misfire is occurring in more than one cylinder. In many cases, it’s due to an ignition timing problem, but when intake or exhaust components are replaced, it can cause these type of problems; especially if during the replacement of the part an electrical harness to a sensor or other ignition system component may have been damaged. I would recommend reading this article on this P-0300 code so you can review the possible replacement services that should resolve this problem. Unfortunately, fixing a random misfire is truly a hit and miss process.

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