What could cause codes p0171 p1171 p0440 and p0506

Jeffrey04
Posts: 3
Joined: Sun Sep 20, 2015 7:08 am

Looking for a diagnostic program/application for my PC.

Unread post by Jeffrey04 » Sun Sep 20, 2015 9:09 am

Hello new member here,
My vehicle is a 2004 Chevy S-10 ZR5 model with a 4.3L engine and automatic transmission with 256,000 miles
For the last several months I have had misfire codes out the wazuu. I have taken the truck to a dealership 3 times for this issue and every time they tell me it's fixed, 30 miles down the road (interstate speeds) SES light will flash at times (especially going up inclines) and eventually the SES light will stay lit.
I have done a lot of research on many different forums and have replaced many parts, which have helped, but it's still not fixed. (I can make a list of everything I've done, if you want.)
So, rather than take it back to the dealer, I would like to have my own diagnostic tool that I can install on my PC so that I can observe exactly what's going on. I've never used a tool like this but I am capable and eager to learn how to use it. I'm a do it yourselfer kind of guy. I would also like this diagnostic tool to have a "re-learn" feature also. I would appreciate any suggestions to point me in the right direction.
Thanks for your time,
Jeffrey
P.S. Today, I am going to pull the spark plugs and check the gaps. Which is .60 per factory specs.

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carriedi
Posts: 2573
Joined: Wed Apr 10, 2013 12:42 pm

Re: Looking for a diagnostic program/application for my PC.

Unread post by carriedi » Tue Sep 22, 2015 10:14 pm

I don't know of any automotive diagnostic programs like you are talking about. If there was one I would be interested in that. Using a good scanner and being able to understand what it is telling you would be key to diagnosing a problem. (good scanner could run $3000 to $10,000depending on what it has in it. but used could be a lot less.)

Here's the thing, you could be looking all over the computer and hardware parts and overlook a mechanical problem. Always start with the basics.
Browse "SIMILAR TOPICS" At The Bottom Of This Page.

MichaelT
Posts: 1
Joined: Wed Jun 08, 2016 3:23 am

What could cause codes p0171 p1171 p0440 and p0506

Unread post by MichaelT » Tue Jun 14, 2016 4:23 am

I'm getting all these codes on my 96 2.2l I have replaced plugs wires air and fuel filter checked all evap system components air intake fuel pressure everything's seem to be good but still can't drive it cause it just don't have any power under a load can put it in neutral and it revs fine but don't when it's in gear

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carriedi
Posts: 2573
Joined: Wed Apr 10, 2013 12:42 pm

Re: What could cause codes p0171 p1171 p0440 and p0506

Unread post by carriedi » Tue Jun 14, 2016 10:45 am

I would look at your O2 sensor and fuel trims first. Use a fuel gauge to measure your fuel pressure. See if it's within spec. From the low idle speed code it doesn't sound like you have a vacuum leak because unmetered air will usually cause a higher idle.

for the codes p0171 and p1171 you should check your fuel pressure. (41 - 47 psi) From your codes, you should look at your fuel trims. (short term and long term) See if the computer is adding fuel to try and make up for the lean readings it's getting from your O2 sensor. Look at the O2 sensor and see if it is switching from above .8 volts to below .2 volts back and forth. Check your injector pulse width to see if the computer is leaving the injector open longer to add fuel to the system.

the evap code p0440 means that your computer see a problem with the ability of your fuel tank system to achieve hold vacuum to the programmed specs it is looking for. So a switch not working correctly, a tank sensor not reading correctly or the system has a leak.

P0506 will be set if your idle is too low. The computer has a desired rpm that it tries to make the engine idle within a certain parameter. The codes sets if the rpm is 60 rpm or more below the parameter it is looking to see. Use your scanner to look at the IAC reading to see what the computer is doing to raise the idle.
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