2005 suburban 5.3 surging on highway under load

[Sstevieboy0208]

they stopped using the inline fuel filters I think in 2002-2003, I can't remember I think my 03 silverado had one, the 04 suburban did not

Well my next step is to test / check the MAF then tune up since it's due for it. I'm still a thousand from oil change so thinking about adding that blue devil now and see if does anything by then. But the issue is that I added STP about 2 weeks ago to the oil. Would that effect it or should I just add the blue devil on top of it ? Or just do oil change first?

 

[Fless]

they stopped using the inline fuel filters I think in 2002-2003, I can't remember I think my 03 silverado had one, the 04 suburban did not

The Flex Fuel engines have inline fuel filters, at least my '04 does. Driver's side, close to the frame member.

 

[Doubeleive]

The Flex Fuel engines have inline fuel filters, at least my '04 does. Driver's side, close to the frame member.

hmm the 05 we picked is supposed to be or is maybe flex fuel I will have to check it out, doesn't have the yellow fuel cap though

 

[Fless]

hmm the 05 we picked is supposed to be or is maybe flex fuel I will have to check it out, doesn't have the yellow fuel cap though

If it's like mine it had already been changed to a black one. I changed it back. It should show FF on the back of the fuel door.

 

[PNWYukon]

Well my next step is to test / check the MAF then tune up since it's due for it. I'm still a thousand from oil change so thinking about adding that blue devil now and see if does anything by then. But the issue is that I added STP about 2 weeks ago to the oil. Would that effect it or should I just add the blue devil on top of it ? Or just do oil change first?

Fuel Pressure: (Key ON, Engine OFF) 385-425 kpa (55-62 psi)

Fuel Injector: If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading.

 

[Sstevieboy0208]

So a new update. On my way to work today it did act up and finally threw 2 codes P0300 and P0306 which is cylinder 6 misfire. So any idea other than just a tune up ? The P0306 showing pending

 

[afpj]

When's the last time you changed plugs and wires, and what did you put in If so? These engines are somewhat picky about what plugs and wires to use.

 

[Sstevieboy0208]

When's the last time you changed plugs and wires, and what did you put in If so? These engines are somewhat picky about what plugs and wires to use.

I actually got the truck 6 months ago so history on it is not the best. I was thinking of putting plugs in but not sure about wires. Also bank one sensor 1 was bad so I replaced it. The misfire is on bank 2 and from everywhere I looked it's recommending replacing the O2 sensor on that side. Since the other one is only a few weeks old and about 2 weeks after replacing it that's what happened

 

[afpj]

It's generally recommended to replace O2 sensors in pairs, as in sensor one for both bank 1 and 2. Many have found that if plugs haven't been changed for a bit ( like 100k miles) the wires will shred when you try to pull them off.

 

[Sstevieboy0208]

It's generally recommended to replace O2 sensors in pairs, as in sensor one for both bank 1 and 2. Many have found that if plugs haven't been changed for a bit ( like 100k miles) the wires will shred when you try to pull them off.

Then that's what I will go with. And will post results soon