check engine codes

[DJ]

Ok, I have had a check engine light on for a while. My inspection expires at the end of the month, and being on a tight budget, I decided to attempt looking at the problem again.

When I connected by code scanner, I was VERY surprised to see I now have 4 codes. Story of my life. When it rains it pours right?

Here are the codes:

P0442: Evaporative Emission Control System Leak Detected (small leak)

P0455: Evaporative Emission Control System Leak Detected (no purge flow or large leak)

P0171: System too lean (Bank 1)

P0174: System too lean (Bank 2)

The P0442 is the one that's been on for a bit. I am guessing that it got worse causing the others.

So far, I have replaced the gas cap, replaced the fuel filler neck, and cleaned the MAF sensor probes. I reset the codes, about 8-9 moths ago, and the P0442 came back rather quickly. I do not know when the other codes came back.

I have an extra MAF from the junkyard that I will clean and pop in, which will hopefully take care of the 171 and 174 codes.

What do you folks recommend for the 442/455?

I am not sure where to start.

Thanks

 

[Chikar]

DTC Code P0442

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DTC Code:

P0442



Description: Evaporative Emission System Leak Detected (Small Leak)



Probable Causes:

1.Sensor or solenoid faulty
2.Connector terminal contact is damaged or corroded
3.Wire harness - Check harness for correct voltage, open, short to ground or short to voltage
4.Update control unit software - Check for the latest control unit update
5.Powertrain or Engine Control Module faulty
6.Vacuum leaks, damaged hoses or improper routing
7.EVAP system - Check fuel cap, canister, valves or components

With a 13 year old truck I'd think item 6 is the most likely, followed by 7.

 

[swshawaii]

So far, I have replaced the gas cap, replaced the fuel filler neck, and cleaned the MAF sensor probes.

Have you checked ALL the hoses connected to the EVAP canister?
They've been known to split, clog, or come loose under there. GL

http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=113362
http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=114194

 

[wessker96]

I have an extra MAF from the junkyard that I will clean and pop in, which will hopefully take care of the 171 and 174 codes.

Could be MAF, or another vacuum leak, but my guess upper and lower mandifold gaskets. Does it have an issue starting or staying started on cold mornings?

 

[wessker96]

DTC Code P0442

--------------------------------------------------------------------------------





DTC Code:

P0442



Description: Evaporative Emission System Leak Detected (Small Leak)



Probable Causes:

1.Sensor or solenoid faulty
2.Connector terminal contact is damaged or corroded
3.Wire harness - Check harness for correct voltage, open, short to ground or short to voltage
4.Update control unit software - Check for the latest control unit update
5.Powertrain or Engine Control Module faulty
6.Vacuum leaks, damaged hoses or improper routing
7.EVAP system - Check fuel cap, canister, valves or components

With a 13 year old truck I'd think item 6 is the most likely, followed by 7.

and yeah I agree