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Discussion Starter #1
I'm getting DTCs; P0171 and P0174 - Fuel Trim System Lean Bank 1/2. I've had my HP Tuner for a few weeks and just this past week-end connected to the GTM for the first time. Has anyone else encountered these DTCs? After cleaning the MAF and checking making sure there are no intake or vacuum leaks what values do you adjust using the HP Tuner to get rid of these DTCs?
My engine is an 2004 stock LS6, 15Kmile with 3" dual filter CAI.
 

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I'm getting DTCs; P0171 and P0174 - Fuel Trim System Lean Bank 1/2. I've had my HP Tuner for a few weeks and just this past week-end connected to the GTM for the first time. Has anyone else encountered these DTCs? After cleaning the MAF and checking making sure there are no intake or vacuum leaks what values do you adjust using the HP Tuner to get rid of these DTCs?
My engine is an 2004 stock LS6, 15Kmile with 3" dual filter CAI.
Vidal,

I'm far from an expert, but on the 'Two Guys Garage' from this weekend, they were working on a C5 and had minor fuel trim problems. All they did was use a special dedicated fuel system cleaner that they connected to the fuel rail which was pressurized with air to 50 PSI. Then they pulled the fuel pump relay so the engine was running just on this high strength fuel cleaner. After they were done they added a can of fuel injector cleaner to the fuel tank. I don't believe that they changed anything with their 'tuner..

So what I'm saying is, it seems like all they did was clean the fuel system and didn't touch anything with their tuner. Look for the episode. It's probably repeated during the week sometime. But like I said, I don't know anything about tuner capabilities myself.

Mike
 

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Vidal,

Checked my Corvette Service manual and it talks a lot about vaccum leaks as possible reasons. Vaccum hoses and connections/intake manifold/injectors/throttle body/AIR system (also shut off valves not closing)/crankcase vent leaks.

Also not enough fuel/contaminated fuel giving too low fuel pressure.

Another thing it lists is to check installation of and connections to the O2 sensors and exhaust leks upstream from them.

As for the O2's the value should be between 200-800mV.

Not an expert, just checked my manual. :confused1:

HTH

/Thomas
 

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Discussion Starter #4
Vidal,

I'm far from an expert, but on the 'Two Guys Garage' from this weekend, they were working on a C5 and had minor fuel trim problems. All they did was use a special dedicated fuel system cleaner that they connected to the fuel rail which was pressurized with air to 50 PSI. Then they pulled the fuel pump relay so the engine was running just on this high strength fuel cleaner. After they were done they added a can of fuel injector cleaner to the fuel tank. I don't believe that they changed anything with their 'tuner..

So what I'm saying is, it seems like all they did was clean the fuel system and didn't touch anything with their tuner. Look for the episode. It's probably repeated during the week sometime. But like I said, I don't know anything about tuner capabilities myself.

Mike
Mike,
Thanks. I have it on my DVR. I'll check it out this evening.
 
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