New Hoe Owner. First debacle

[rockola1971]

Thanks! will do. Appreciate the insight. In the meantime I am gonna see what I can do about the leaking transfer case. never a break.

Look for a small hole on the passenger side rear of transfer case about 2" up from the bottom. Known problem (Pump Rub) with our NP246E transfer case.

 

[Verd]

Look for a small hole on the passenger side rear of transfer case about 2" up from the bottom. Known problem (Pump Rub) with our NP246E transfer case.

Damn that guy makes it look easy. very informative thank you

 

[jarydM]

Picked up a 04 Tahoe with about 180k on it for a good price. Always wanted one, and my S10 got creamed during this years winter storms in front of my house so i figured why not. The truck has its issues that need addressing and that's fine.

So the other day i was driving down the parkway doing about 70ish, and the check engine light popped. When I purchased it I got a P0174 but no check engine light was on. Now after checking it since I have also P0171. I have researched it and I checked the usual suspects, intake gaskets being one of them, and they seem fine and actually the truck runs fine by all accounts so this had me perplexed.

I tossed on my fuel pressure gauge and I am showing 35 psi with the key on and 50-55 with the engine running. I believe this is too low and could be why I am throwing lean codes. Then come to learn the 5.3 model i have does not have a serviceable fuel filter so my question is, is it a safe bet to order myself a fuel pump? Any suggestions I check anything else before going for the money? Thanks ahead of time. I know this question is asked a lot but it seems the solutions have varied.

When I had that code Was worried about fuel pump too, but i replaced the upstream O2 sensor on the affected bank, and all was good.

 

[HiHoeSilver]

When I had that code Was worried about fuel pump too, but i replaced the upstream O2 sensor on the affected bank, and all was good.

This is why I said the sensor first. I know the parts store guy with his scanner says, "its your o2 sensor" every time no matter what... But, seriously, it might just be the sensor.

 

[Tacky]

Dirty MAF might set a different code, might set fuel trim codes. I would try cleaning it, and making darn sure there are no air leaks between the MAF and the thrttle body, and check the PCV pipes fr leaks If it holds 50-55 psi fuel pressure while driving, including WOT acceleration, I would say the fuel pump is OK. Since it set both P0171 and P0174, lean on both banks, I doubt it is O2 sensors. I would try running a couple tanks of top tier fuel (toptiergas.com) with a can of injector cleaner added and see what that does for you.

 

[HiHoeSilver]

Dirty MAF might set a different code, might set fuel trim codes. I would try cleaning it, and making darn sure there are no air leaks between the MAF and the thrttle body, and check the PCV pipes fr leaks If it holds 50-55 psi fuel pressure while driving, including WOT acceleration, I would say the fuel pump is OK. Since it set both P0171 and P0174, lean on both banks, I doubt it is O2 sensors. I would try running a couple tanks of top tier fuel (toptiergas.com) with a can of injector cleaner added and see what that does for you.

Good point about it being both banks.

 

[oldchev]

I have the 6.0 but they both work similar. Mine had an intermittent fuel pump failure that was hard to get a pressure reading on. Loss of fuel pressure will get both codes but I discovered it has to get pretty low (under 10 psi) at idle to stumble. Look at YouTube and search "fuel trim 101". There is a lot of info there about these two codes. I also watched a guy show how he used water (copious quantities) to check intake gasket failure. Like another said that gasket failure would usually be one side or the other. A consorted effort to diagnose the issue will save $$ and keep from just throwing parts at it, although you could get lucky. Keep us informed.