2013 Equinox 2.4L, no power at 4k+ RPM, minimal codes

[Dragonary]

So last week I noticed an issue where my Equinox would go into the high rpms on my normal drive to work (headwinds can cause this to some degree) which includes some highway driving. By the second day I knew something was wrong. I have a bluedriver scan tool. I read the codes and saw a P0014 plus a P0411 that I've had for a while that I need to keep diagnosing. For the P0014, I replaced the intake and exhaust cam solenoid valves, but the problem remained the same. I took it for a drive and the check engine light didn't illuminate, but it still have the performance issues. I changed the spark plugs because it's been a few years, but that didn't really change anything. The car idles and seems to run fine until I start getting above the 3k RPM range.

I gave it max throttle to push it a little more about 4k RPMs at about 60 MPH and then I got a flashing check engine light and a service stabilitrac message. I read the codes and I only got P0300 and U0401. I can clear the codes and repeat this process and get the same thing. I did also find some evidence of chewed wires possibly by a rat going to one of the connecters on the ECM. The wires weren't completely broken, but I ended up repairing them with splices and it didn't change anything. I've looked around for more damage but haven't seen anything. Anyone have ideas or experience anything like this?

 

[Dragonary]

I forgot to mention but this also happened right after filling up my tank so maybe bad gas? I put 3 gallons of 91 in it after burning some a few days ago, but it didn't really seem to make a difference. I just went on a drive to burn more fuel and check some of the sensor data. Fuel pump looks like it ranges from 38-53 PSI, fuel rails 400-1900 PSI. MAF 0.4-10.9 lbs/min. No check engine light or other codes. I did not push the engine to have the misfiring occur.

 

[Dragonary]

After more driving and other troubleshooting, I'm going to replace the high pressure fuel pump. I had P0172 pop a few times. My long term fuel trim is also fairly negative (around -9%). I added more gas and nothing changed. I think it's probably in the fuel system as it isn't just 1 cylinder giving me problems. If this doesn't fix it I may change the fuel pump in the tank because it seems like it isn't holding pressure.

One of the diagnostics says to engage the fuel pump with the engine off and get it as high as it will go (50-100PSI) then see if it drops down to 72-87PSI and doesn't drop further than 5 PSI in 1 minute. I don't have a scan tool that will allow me to engage it, but just turning the key on and off I got it up to 70PSI, but it drops to 29 PSI shortly after. This is when the engine was warm. Anyone have any experience with this? When the engine is operating it seems to stay in a consistent range.

 

[Dragonary]

Well it looks like oxygen sensor #1 had some kind of catastrophic failure and clogged the primary cat in the process causing the issue. It actually got worse but that explains it. I bought a pressure tester and discovered it had a blockage in that area. Since replacing the cat and O2 sensors it's been fine.

 

[mirageman]

Thanks so much, man... It's frustrating sometimes when people don't chime in, like you're talking in an empty room, but you help others who come here looking for insight on issues.

 

[DannyW]

I know I'm late to respond but I am having the same problems you had...although mine started after a long trip my check engine came on with clogged cat. I shut the engine off and after 20 min or so (enough time to eat a sandwhich) I start it and it stalls after I put into gear and press the gas. Had everything done you did(new timing chain, cam phasers aligned, new intake manifold etc. Note..i had a crack ehaust manilfold i found changing 02 sensor) mechanic said cat wasnt the problem so didnt change it. Check engine light for clogged cat came back but It helped for short drives until I drove an hour away then let it sit while we went to an auction. Came back and started it after letting it sit for 25mins and it idled for 30 seconds then died. Started it and made it to autozone and got a new battery. So far no stalling and no check engine but it acts like it wants to stall when I come to a stop every now and then and the radio goes black randomly and the head lights dim im not sure if i need to change the cat im still waiting to see if the code comes back or if it is an alternator issue. I researched on different forums and ALOT of people have the same problems..I called Manufacturer and they said they have no information on issues or recalls and nothing they can do to help