I have a 2005 Monte Carlo Tony Stewart Edition. It has a lot of miles, I just reached 202,000. The question I have is it sputters, or bogs down when I either go up a hill, or hit about 60 on the interstate. The check engine light also flashes for about 15-20 seconds. It only does it in those two instances. It drives fine any other time and the check engine light doesn't stay on. I have replaced the plugs, wires, coil packs, Catallyic Converter and air flow sensor within the past 8 months. It just started doing this within the past three. The only thing I can think of is a fuel injector maybe. Any suggestions on what could be causing it?

 

It would help to know what code it's throwing. You can take it to autozone to get it read. Then we'd be able to give you more advice.

 

The Check Engine doesn't stay on. It just flashes when it sputters and goes away. I

 

Usually the flashing CEL is a random misfire. Could be the fuel injectors, a vacuum leak, or low fuel pressure.

 

DJ_bosse is right, the flashing is normally a mis-fire. But the computer should still have a history of the code thrown (might take a better scan tool that can read that part of the computer). A mis-fire code can narrow you down to a specific cylinder or inform that it's a random mis-fire. Either way, it helps you pin point where to look for the cause of the problem.