Posted: 2/19/2012 1:34:49 PM EDT
| I could use some help on where to start. I am getting 3 codes from my 2000 Chevy Silverado. It has the 5.3L with almost 200K on it. The firsts code is P0430 catalyst system efficiency below threshold bank 2. Then I have P0171and P0174 both banks have a lean condition. I really do not want to start throwing parts at it until I fix what is going on. I can clear the codes but with in 10 drive cycles they return. Where would you guys start? |
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I could use some help on where to start. I am getting 3 codes from my 2000 Chevy Silverado. It has the 5.3L with almost 200K on it. The firsts code is P0430 catalyst system efficiency below threshold bank 2. Then I have P0171and P0174 both banks have a lean condition. I really do not want to start throwing parts at it until I fix what is going on. I can clear the codes but with in 10 drive cycles they return. Where would you guys start? Intake manifold gasket leaking and replace the cat. Intake gaskets can be done in an afternoon. The cat you are going to have to take to a shop for I would wager. To do this you will NEED a good 1/4 torque wrench. |
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Damn, I think i would have noticed some issues with the leaking intake gaskets. I may be wrong though. Brake clean and a scan tool that can show you wave forms for the o2 sensors. It does not have to be leaking enough to cause rough running issues, just enough to make the computer lean out the engine. The 5.3 have issues with the intake manifolds/gaskets. |
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Intake gaskets really didn't start until around 2003 2004. Have not seen many on the earlier GMT900 trucks or suvs.
Def Converter on the P0420. For the 171 and 174. I would not even address them until the converters were replaced. but check fuel pressure and volume. while testing the fuel pressure with the eng running open the pressure release of your pressure tester and see if the truck stumbles or stalls. If so then low volume would could be your problem, also check your mass air flow sensor, oil cap, pcv tube, air intake tube ect... |
| Ok guys, I checked on the codes some more and I cleared the lean codes and they have not returned. The catalytic code keeps coming up. This only happens while I am at idle, and the engine is up to operating temps. The code does not seem to be triggered while driving. I am going to skip the lean condition unless it comes up again. Any ideas why the cat code only happens at idle? Not enough flow and heat at idle to make the cat perform? |
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Ok guys, I checked on the codes some more and I cleared the lean codes and they have not returned. The catalytic code keeps coming up. This only happens while I am at idle, and the engine is up to operating temps. The code does not seem to be triggered while driving. I am going to skip the lean condition unless it comes up again. Any ideas why the cat code only happens at idle? Not enough flow and heat at idle to make the cat perform? Because the cat is bad. Just throwing that out there. |