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Troubleshooting hesitation in 2.4L ecotec


QuaTTro
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I'm trying to help a friend who is troubleshooting hesitations in a 2.4L Ecotec in a 2013 Chevy Equinox.  Not exactly race car related but with the experiences of the teams here (in general and with ecotec's) I'm hoping to get some ideas that will help him.  NOTE:  This friend is a trained Audi mechanic who has worked on euro cars for over 20 years), so he has good skills but doesn't know much about Chevy's.

 

The questions:

1. Is there a software he can buy for troubleshooting this engine.  He's used to using VAGCOM for the Audi/VW stuff and wondered if there is a good option like this for the Ecotec.  Something that let's him better diagnose or change settings.  

 

2. Can he try an ECM from another Equinox?  Or will there be issues because the ECM is coded to the car for security reasons or whatever?  He's curious if the issue is a bad ECM but wasn't sure if he could just plug in an ECM from a junkyard Equinox

 

The Backstory:

Initially the car had a timing issue and the head was damaged.  The head was replaced, along with the exhaust manifold that was cracked, new 02 sensor, and new catalytic converter (he thought the CEL codes above might've been 02 or cat related).  CEL codes happening include P013E (02 sensor delayed response), P2271 (Signal Stuck Rich), and P0138 (02 Circuit High Voltage)

 

Some days the car drives perfectly, and other days it will have bad hesitation on throttle and get the codes listed above.  It's very intermittent and there doesn't seem to be a pattern to it.

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I’ve just recently replaced the entire wiring harness on my 2.4 Cobalt. The wiring to the O2 sensors is especially susceptible to getting hard and brittle and causing issues.  
 

You can use HPtuners to change and diagnose pretty much anything ECU related.  But you’ll need credits for both ECUs so it may not be cost effective to do that just to troubleshoot.   

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An update after speaking with my friend.  He says that when the car starts stumbling/hesitating.....the way the driver makes it go away in that moment is to power cycle the car.  Sometimes it's an instant resolution (car in neutral while rolling and key cycle it), and other times they have to park the car for 15-20 seconds.  But ones of these methods works evertime and they keep driving ok afterwards.

 

He's checked the 02 sensor wires and including visual check and with multimeter on the wires (including the heat wires).  They all seem ok.

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We got a better data logger/reader.  Looks like when the car acts up, the Calculated Load is going to 100% and the pressure at the fuel rail increases like 5x.  This happened when just cruising casually at 65mph.  After a minute or 2 of trying to drive through the hesitation today the car just "self corrected" and went back to normal driving without needing to restart the car.

 

So now we will look into why the load suddenly jumps to 100% when there's no change in throttle position or load in general.

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