Ultimate fix may well entail a smoke test of the evap system to locate a small leak.
Find shop with equipment/experience in this area.

 

Yep that's what I'm thinking, I just wanted to check here first to see if anyone else has had the same luck that I've had with this pesky code.

on my 2010 the evap canister within drivers rear quarter panel fixed my evap error code ( i don't know the number off the top of my head but you didn't reference the canister in your original post so i thought i would). the evap module on top of the motor did not resolve the issue initially.

Yep I've replaced that evap canister too a few weeks ago along with the evap module on top of the motor, at the time of my post I couldn't think of the correct name. I think this is the third evap canister I've bought in the last 3 or 4 years trying to fix this issue LOL.

Im dealt with that on my 2012 LTZ. I changed the front 3 spark plugs and everything was fine, then I changed the rear 3 and got a rough idle and that P04442 error. I replaced the Vapor Canister Purge Valve / Solenoid with ACDELCO 12610560 and it came right back, so I cleared the codes again disconnected the battery and the code went away, but still have a rougher idle since changing the rear 3 plugs.

That's the same canister I bought a few weeks back. Kinda stumped, here. Don't really want to take it to a shop for a smoke test but that's looking like my only option unless anyone else has any other pointers on what could be causing it?

I was really wondering if anyone else had taken their car in for a smoke test for this particular code and what was the cause?

 

on my 2010 the evap canister within drivers rear quarter panel fixed my evap error code ( i don't know the number off the top of my head but you didn't reference the canister in your original post so i thought i would). the evap module on top of the motor did not resolve the issue initially.

 

Im dealt with that on my 2012 LTZ. I changed the front 3 spark plugs and everything was fine, then I changed the rear 3 and got a rough idle and that P04442 error. I replaced the Vapor Canister Purge Valve / Solenoid with ACDELCO 12610560 and it came right back, so I cleared the codes again disconnected the battery and the code went away, but still have a rougher idle since changing the rear 3 plugs.

 

Log some tank pressure data and take a look in this thread for leaking and properly operating evap system pressures.

P0455 troubleshooting w/ data logging

Hello, I've been having a recurring P0455 (EVAP large leak) over the past few months. It started off with the 'Tighten gas cap' message, and began throwing P0422 (EVAP small leak) and then P0455. I've also had an occasional P0014 (Bank 1/B camshaft over advanced) code which I think is unrelated...

www.impalaforums.com

If you aren't getting tank pressure readings like the above thread then the tank pressure sensor has failed.

If you're seeing changing tank pressure changes then hook it to the smoke machine.

You can DIY a smoke machine and use Baby oil for the smoke. You can buy the bladder to plug into the intake or the filler neck.

 

FWIW my brand new supposedly correct and well reviewed aftermarket gas cap for my '11 Impala just does not feel right when clicking in, not positive. Gasket looks good. I got the code P0442 and had an old cap with a worn gasket so I replaced with this. I have seen a lot of comments that sometimes the aftermarket caps just don't seal well. Mine is still throwing the code every week or 3 but I just adjust the cap and clear it cause I'm not particularly worried about that code. Will try an OEM cap or maybe an extra little gasket on top of the one in the aftermarket cap. YMMV. Seif.

 

That is before I start throwing any other parts at it..... My state does not have any emissions testing BTW :>)

 

Have you looked at your Purge Valve? I was getting the P0442 on my '16 Limited LTZ. Here's what I found:

This was the factory installed part. If yours looks good, use a little lube. Don't put it back in dry.

 

You can make a DIY EVAP smoker;
You need an air compressor you can regulate the output down to 2PSI or so or a bicycle pump.
Fairly elegant smoke machine. Probably costs around $20-$25 in parts.

Really ghetto but it'll work. This is a glass jar so care must be exercised to keep from needing to clean glass shards off the shop floor.

Here's how to smoke the EVAP system with any smoke machine. The Ready Smoke is sexy as hell but it ain't cheap.
Notice how he uses the laser pointer.

 

P0442- Small EVAP Leak Detected

Is it just me? Or does anyone else think P0442 is the code for your Impala impersonating an Olds Cutlass trim level?


Doug

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