2002 Chevy 1500HD 6.0

runs rough, lacks power and can feel it misfiring.

initially ran like **** almost wouldn’t stay running had new parts laying around and ordered some so I did
recently intake gaskets, knock sensors, valley pan gasket, new alternator not a reman, plugs, wires, air filter, cleaned MAF and throttle body.

after all the work listed above it runs somewhat better but still have lean codes and misfire codes. Have just a code reader and freeze Frame shows longsft1&2 at 25% with engine at 200 degrees, spark advance is 5

i pulled the fuel rail vacuum line off while running had no fuel leak out and today did a fuel filter when I did the oil change drive it around still have if same codes and symptoms. So bad at times can’t even overtake a car on the highway.

many ideas?

 

What is your fuel pressure? Factory spec for non-Flex 6.0L engine is 55 - 62 psi. If you do not have a fuel injection pressure gauge, you can use the loaner tool program at most O'Reilly, Autozone or Advance auto parts stores.

If you have a Flex fuel engine the factory spec for fuel pressure is 48 - 54 psi.

Good Luck!

 

52psi at the rail was talking to a friend that owns a shop she was thinking since I’ve had no luck so far to try to temp at the cat and could be blocked since it’s high mileage it’s at like 350k on the odometer.

I also made a home made smoke machine from a video on YouTube with some mineral spirits and a mason jar worked really well actually found a very small leak around the EGR at the intake I ordered a new gasket for it.

 

 

I noticed a couple of things. One, Short Term Fuel Trims are not being reported, and Two, the engine temperature is showing up at 70 Deg F. Also, the engine/Fuel System is in Open Loop mode meaning that the Long Term Fuel Trim values are for all practical purposes meaningless.

What do you get when the engine is warmed up to normal operating temperature and the engine/Fuel System is in Closed Loop mode?

 

I can’t seem to capture it when it’s up to temp. I drove an hour home from work today tried to capture when driving and when I got home. Freeze frame is still reading 56 for the etc is there a specific way to capture it?

I also just put ac Delco upstream o2 sensors in the left one was covered in oil at the electrical connection, I assume from an old oil leak the right one seems clean at the plug

 

New code po507

 

First, the P0507 is telling you that the idle is too high and there is a problem with the idle control system. Most likely cause is a vacuum leak.

As far as how to get your code reader to read what is happening "now" and be able to capture a current freeze frame data, you will need to read the instruction manual for the OBDII code reader/data scanner.

OK on replacing the replacing the upstream O2 sensors.

Also, if your fuel pressure is only 52 psi, that is lower than the factory spec (unless you have a flex fuel engine) so keep an eye on it as the pump is likely beginning to fail.

 

not a flex fuel engine I do have another fuel pump I pulled out of a wrecked truck I’ll throw in and see about psi change I was able to capture freeze frame at close enough to at temperature.

I was able to capture 2 sets of freeze frame data. The really zoomed in pictures at the bottom (1-3) are from at 06:30 this morning.
the first set where you can see more of the device and my finger at the top are from this afternoon at about 14:30.
I do live in the eastern shore of Maryland and has been raining today. Also since I’ve replaced the o2 sensors it seems that it may not be as sluggish and the check engine light definitely takes longer to come on today. Usually it comes on about 30 seconds from startup on a cold start but this Morning it took about 15 minutes of drive time to come on. Only showing the lean codes and misfire codes

 

OK on replacing the O2 sensors & being on the Eastern Shore - I'm on the other side of the Bay.

Well, according to the new pictures, you are headed in the right direction. You know have a proper engine temperature so the thermostat and Engine Coolant Temperature (ECT) Sensor are working properly. The engine is in closed loop so the ECM is using the information from the O2 sensors.

Now some questions:
What brand Spark Plugs did you put in?
What brand of spark plug wires did you use?
What brand of MAF sensor did you use?

I ask the above because not all parts are created equal and some very common brands do not have very good track records. Also, the Vortec engines really do not like non ACDelco plugs and you should be using 41-962 Double Platinum plugs.

Also, regarding the fuel pump, I would only use an ACDelco/GM Genuine fuel pump in order to avoid having to replace it again. I used to also recommend Delphi fuel pumps, but their quality seems to have nosedived over the last couple of years. Now, the thing you will need to know when getting the fuel pump is the number of electrical connectors are going to the fuel pump. You should be able to get a peak at the fuel pump by jacking up the rear end and removing the driver's side rear tire. Now, contort your body so you can look between the bottom of the truck bed and the top of the fuel pump. No you should be able to see if there is one or two connectors and then you will be able to select the proper fuel pump.

Good Luck!