Q: P0201 and p0301 code with new injector, coil, sparkplugs and wires and replaced ecm

asked by on November 29, 2016

I recently replaced ecm, spark plugs, wires, coil, new injector and it still is misfiring with check engine light and p0201 and p301 codes... I need to smog my van and dont know what could be causing this
My car has an automatic transmission.

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Hi there. As you already know, replacing components without diagnoses can be expensive and time consuming without resolution. Circuit testing for the P0201 (#1 cylinder injector circuit fault) code needs to be performed to isolate the injector circuit fault. This could be done using an DVOM (digital, volt , ohm, meter), checking for a voltage signal to the injector and a resistance value test from the injector to the ECM (engine control module). Resolving the P0201 code, more than likely, will resolve the P0301 (#1 cylinder misfire) code. I recommend having your vehicle’s check engine light be diagnosed and repaired by a certified technician, such as one from YourMechanic.

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