acdblujns

I have a 2005 Express 3500 that's been giving me some trouble. It randomly stumbles and loosed power once things get warmed up, it also comes and goes. It never stays so I can say just what the trouble is.

I've checked the codes and this is what It gave me.

P0059 HO2S Heater Resistance (Bank 2, Sensor 1)
P0152 02 Sensor Circuit High Voltage (Bank 2 Sensor 1)
P0157 02 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0300 Random/Multiple Cylinder Misfire Detected
P0430 Catalyst System Efficiency Below Threshold (Bank 2)

From all the research I've done it looks like the O2 sensors are possibly bad, and maybe the Cat is also. The hard part is diagnosing the P0300 Random misfire code.
One other thing the Traction control light comes on when the misfiring is occurring.

Can anyone shed any light on this?
Thanks,
Pat

canucklehead

The misfire is likely a by product of the other codes.
i would replace the o2 sensors if they are original......past due.

CNG Pete

I having some similar issues with some of the same codes.

Misfire can be from almost anything. Its sort of a generic code that you play hide-and-seek to find the source.

I dont believe the O2 sensors age would make a misfire, but stanger things can happen on these newer vehicles!

My initial fixes that did cure the misfring temporarily was finding some damaged wiring on the coli connectors. Take off the coils and inspect yours.

-Pete

canucklehead

i am not up to speed on the new engines. The 02 sensors can affect fuel mixture and timing to a degree. I had a misfre and it was the dizzy cap, and your engine does not have one.....
Maybe the bad sensors have fouled up a spark plug.....

purodude

I work as an owner operator for a large courier company. There are 30 trucks in the fleet about half of them are express/ savana cube vans. All the newer ones had the same problems as you describe. One of the guys spent thousands of dollars trying to fix the lean cods and check engine light problems. He did everything from fuel pump to intake gasket none of which did anything. Until he found a little corner garage with an old mechanic with 50'years of experience under his belt. Here's the kicker all you have to do is get a injector service. Now not the crap you buy at your local car parts store. A professional service. Where they hook up directly to your fuel system and flush all the crap out of the system. Apparently there is no fuel return line on the 6L so all the junk just piles up in the injectors.
Now since we came across this information every Chevy gmc truck in the fleet has had the codes and misfire problem and EVERYTIME this fix has worked.
I hope this helps.