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2000 Impala 3.4 L

I just replace the engine in my car and I had new plugs and wires put in as well. Ever since the new engine, the car doesn’t go up hills well and it is very sluggish from a stand still position. As long as I am driving on a flat surface I am good once I get up speed. I went to autozone and I got a P0300 code. Is this a bad ignition coil or maybe a clogged catalytic converter? Thanks.

That code should be for a random misfire and the first suspect might be the crankshaft position sensor.

I’m also assuming by new engine that you mean a new or remanufactured engine, not a salvage yard unit.

Is the CEL flashing?

To be honest it is a salvage unit, and the cel is flashing.

the code is for a randome mis fire sould be a crank or a cam sensor. did you hear the engine run b4 you put it in the car?

A flashing CEL is VERY BAD… It is telling you that if you keep driving the car, damage WILL happen. Who sold you the motor? Did you get a warranty? You may need it at this point… Have you been looseing anti-freeze by any chance?? I have a theory… Let me know about the antifreeze

Yes I do have a warranty. I have not had any lost with anti-freeze.

I wonder whether that new engine is timed right. No doubt it is a rebuilt engine?
Maybe the belt is one tooth ahead of where it should be.

I would double check to make sure the plug wires are properly installed in the right positions. However I would not drive the car until that flashing CEL has been addressed as a flashing CEL can indicate a situation that could cause damage in you attempt to drive it.

@RemcoW: “No doubt it is a rebuilt engine?”

OP says it’s a salvage engine.

I’d want to make sure there’s nothing wrong with the timing. Salvage can mean you bought someone else’s trouble.

Hey guys, I wanted to give you all an update on my situation. My catalytic converter was clogged and being that money is an issue I had it straight piped. I will save up to get a new one so that I will pass my emission test. As far as the random misfire and the flashing CEL. I had two wires crossed on the tuneup. When the wires was placed in its proper alignment on the ignition coil the misfire went away. The CEL ins’t flashing anymore.