3400 help needed.

[PERM01]

Sorry for this being the first time post but I'm in need of help ... the GA isn't running so hot. It started out suddenly as a slight "chug" when barely trying to maintain speed and now it's a miss at idle and slow acceleration also. The first code I got was P0141 then yesterday I got P0303. Checked the plug and wire in cyl 3 and all looks well. Any help is appreciated.

[geoffinbc]

Sounds like misfire. When was the last service done and with what parts? Plugs are often the cause but it can be wires, coil packs or ignition module.

[sprucegagt]

P0141 - Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 2

P0303 - Cylinder 3 Misfire Detected

That O2 sensor is after the catalytic converter. Add in increasing poor performance with a misfire code and I would start looking for a plugged converter.

[PERM01]

But the problem came on instantly. Can a plugged cat be fine one day and show symptoms the next? Also wouldn't I notice performance loss with a plugged cat? The car runs good under normal and heavy acceleration.

Plugs are newer wires are older. I pulled the plugs and wires and all look good.

[sprucegagt]

It helps to have more information.

Yes a plugged cat can be fine one day and bad the next. But what your explaining sounds more like a fuel injector getting dirty.

[gar70614]

icm or coil mabey i had similer symptoms on my cav and it was the icm

[96GPSE]

I had a similar issue, cylinder misfire on 6, turned out to be a leaking fuel injector. I pulled the rail and set a rag under it, then primed the pump by turning the key on. Sure enough, the injector for #6 was dripping fuel. Replaced the injector and all was well.