Hi All,

I have a 2005 RAM 1500 SLT 4.7L at just over 150000 Km. I've been having problems with it Bucking and Lurching while accelerating, and it occasionally stumbles while idling. For a while it would hesitate/bog down when accelerating from a stop and I had to goose the throttle to keep it from stalling.

I had a the CEL come on a while ago throwing a p0420 code (Catalyst System Efficiency Below Threshold), and I continued to drive it as I didn't have the cash to fix it at the time.

Anyway the other day it was really rough up the hill to my house and the CEL started flashing, so I checked the codes and it was reading p0420, p0406 (Exhaust Gas Recirculation Sensor A Circuit High), p0405 (Exhaust Gas Recirculation Sensor A Circuit Low) and p0305 (Cylinder #5 Misfire Detected).

After researching on the internet I have replaced my plugs, replaced the EGR valve and replaced the TPS and cleaned the TB. All codes cleared, was idling perfect after the TPS was replaced and TB cleaned, it ran well for about 5 KM and then started lurching/bucking and stumbling occasionally at idle again.

I'm at a loss, my research seems to point to possibly a bad Cat or Fuel Filter. I did the paper test and it does get sucked back against the tail pipe every few seconds, but no smell or hot manifold. A drop in Cat is about a hundred bucks not sure on the filter.

Anyone have any ideas what the next step should be?

Thanks in advance,

Mike

 

Nobody?

 

It sure sounds like the cat to me, could also have caused that misfire. But after a misfire code and with it stumbling under load I'd keep an eye out for any coolant in the oil as well, just as a precaution...