Rough idle, slow acceleration

[jlio]

I was running late, so I started with some quick shifts and high revs right out of a cold start, then a stop and a quick u-turn. Within sixty seconds (right after the u-turn) I noticed that my acceleration had gone from peppy to pathetic. I drove about 40 miles and went from 1/2 a tank to 1/4, which is about 20 more miles worth of gas being used for the trip. The CEL was flashing when I was going over 40 mph, but steadied out at the stops, then back to flashing as I passed 40.

I'm familiar with a wrench, but I've only done the easy stuff: water pump/ radiator/ thermostat on the Chevy, alternator and belts on this one, oil, etc. I don't necessarily know my way around the acronyms, so I'm not going to be much help with the diagnosis. I did look through the forums, and saw a lot about the EGR and exhaust. I have a manual, but I won't get to this until Friday or Saturday. The EGR problem seemed like it should be rough (and low) idle, but mine idles at about 900 rpms with no stalling.

'02 P5. Any help would be appreciated.

 

[Maroon]

Get the engine light codes read at Autozone or Advance Auto.

A flashing engine light indicates a misfire. Inspect your plugs, wires, and coil packs.

 

[jlio]

Misfire on third cylinder. Now I just have to see whether it's the plug or the wire. Thank you.

 

[pcb]

...The CEL was flashing when I was going over 40 mph, but steadied out at the stops, then back to flashing as I passed 40.

If you ever throw a misfire code (P0300- P0304) the ECU puts your engine into limp mode and dumps all kinds of extra gas in to help protect the engine.

 

[dragosurf88]

I had the same problem a couple of months back...CEL...same code...MISFIRE...the coils are known to go bad. I replaced both coils at the same time because one new coil with an old coil will kill the old coil faster....do yourself a favor and replace both at once. I got mine at Orielly, I went for the lifetime warranty version (total cost like $80). I had to go to two stores since each store only stocked one. Very common problem...havent had a CEL since.