I have a 2001 Impala 3.8ltr with 60,000 miles on it. The engine runs so quiet at idle, you don't even know its running. But, this week, at high rpm's, it starts losing power and some slight popping in the exhaust manifold. The code says "Random Cylinder Misfire". I have new plugs, wires, fuel and air filters. Plenty of power on low end.
It's almost as if the electronic timing advance is not working properly. There is no noticeable missing, compared to a plug or wire. It just sounds like it's "starving" at around 4000 rpm.
Any suggestions?

 

Since it's been over 3 days.....I'll answer my own post. It's the catalytic converter. Taking it to the dealer tomorrow. 80,000 mile warranty on the cat................

 

Thanks, I have a 2002 Impala with 67,000 that was doing the same as your car was. Same computer code. I noticed it when I started to pass a car when I was 200 miles from home. The car ran fine at a cruise. By the time I got home after about another 300 miles I couldn't get much over 2200 RPM. Went by the closest dealer with a print out of your problem and my computer code on 22 Dec without the car. I was told to bring it in, they weren't busy. This was at about 1:30. Dropped off the car at about 2:00 PM and got a call that it was ready at 4:20. No charge. Thanks for the help!

 

Hi H8tobl8

I have a 02 Impala that has just gone thru the same problem, I was losing power when I stepped on the gas, and the engine light came on flashing, I got to a local dealer and they checked the code and replaced the catalytic converter no charge.

And just to add, last month I had to replace both front bearings and abs wire harness's. My trackton light and abs lights locked on and the traction contron came on everytime I would start moving, there was a grinding sound and a chattering each time I pulled away, by the way I only have 65,000 Km on this car.

Thanks for letting me vent...

Dee.

 

Im having the same issue with the grinding noise up front. I actually feel it through the gas and brake pedal and also the stearing wheel. Thought it might be the tires since i had 2 new tires put on back and rotated the others to the front when it started to make the noise. But had the front tires checked and they said they were fine, so, it has to be my bearings.