To start have the battery and alternator checked for proper operation. Check for lose connections from battery positive/ground and alternator positive/ground.

Let us know how it goes.

 

All the connections seem to be good. The alternator was changed last summer and the battery was changed couple months ago.

 

I haven't experienced a similar issue, but is seems possible that something is triggering the engine to go into limp/safe mode. I wouldn't be surprised, if that is the case, that the trans would shift funky. Is the engine running O.K. ( idling, accelerating, cruising) when the trans goes into that 4 - speed mode? Does your model have the sport mode where you can shift it manually?

 

Yeah it’s a weird problem. I’ve had this problem for several months now to be honest. The engine did start misfiring few days ago and I ended up replacing the coil packs. Now it’s running smooth… other than when the lights come on. I do have the manual mode and it’s same thing. When I shift to 5th, the dash shows that it’s in 5th gear but in reality it never shifted and it’s still in 4th gear. Same thing if I continue shifting to 6th gear.

 

If you had a scan tool to read live engine data it would help give some direction.

 

I’m going to get one tomorrow. What are we looking for with the scanner?

 

Going to verify that engine is operating within normal specs such as MAF/LT/ST fuel trims A/F and O2 sensors etc.

In addition read codes/erase codes see what codes return first and freeze frame data stored.

 

I use a Wifi/Bluetooth OBD reader that reads live & noncontinuous data; I'd recommend one of those. To spare you some reading, long-term fuel trims should be <10%.

The C codes suggest electrical issues. You could have a bad ground intermittently triggering problems with engine operation. The ECM also controls transmission function. The B1 and B2 grounds are linked to the ECM; check those. B1 is under the engine cover between the banks, and B2 is towards the right. You could also have an intermittently malfunctioning knock sensor for Bank 1, as P0328 suggests.

 

Ok so I bought one of those obd2 readers from Amazon and started doing some reading. I don’t understand most of it but here’s what I’ve done so far.
With the codes still active and the engine still cold I plugged the obd2 and got this results.
Short ft1 -2.3
Long ft1 11.7
Short ft2 0.8
Long ft2 13.3
MAF 5.20
02B1S2 0.015V
02B2S2 0.015V
02B1S1 3.257V
02B2S1 3.275V

Then I warmed up the engine and got the following.

Short ft1 0.0
Long ft1 18
Short ft2 0.0
Long ft2 21.1
MAF 3.20
02B1S2 0.640V
02B2S2 0.680V
02B1S1 3.263V
02B2S1 3.264V

After doing that, I disconnected the battery and let the engine cool down for couple hours and clear the codes. While disconnecting the battery I noticed one of the vacuum hoses going to the intake was popped out and the air intake that goes from the front of the car to the intake box, was popped out both from the intake box and the air cleaner resonator chamber. So after plugging everything back I ran the obd2 scanner again.

Cold engine

Short ft1 4.7
Long ft1 0.0
Short ft2 10.0
Long ft2 0.0
MAF 5.37
02B1S2 0.015V
02B2S2 0.015V
02B1S1 3.247V
02B2S1 3.262V

Warm engine

Short ft1 1.6
Long ft1 6.3
Short ft2 0.0
Long ft2 9.4
MAF 2.56
02B1S2 0.800V
02B2S2 0.800V
02B1S1 3.237V
02B2S1 3.277V

Not sure what any of this means to be honest. I took the car for a test drives after doing the last obd2 scan and the check engine came back with the other lights as well. The obd2 scanner that I got from Amazon only shows the P0328 as active code.
There’s also parameters for EQ_RAT and I’m not sure if those are the air fuel sensor parameters? For example EQ_RATB1S1 0.994. Additionally I noticed my heads are leaking oil as well.

 

You did good by fixing the vacuum leak.
Lt plus st trims below 10 is good enough.

Next is the p0328.
Maybe best to have shop help.
Not familiar with your engine so can't speak to that.
MAF reading a bit low maybe clean should read around 3.5 at hot idle.
May bring ft down if maf reads 3.5.

Let us know how it goes.

 

Lt plus st trims below 10 is good enough.

I wouldn't say the LTFT post-battery-reset is proven. Now there's a small amount of runtime to calculate that data—only one warm-up cycle. Technically, >±5% is suspect. For OP: a positive fuel trim is indicating there is more fuel being added to maintain proper functioning than the ECM expects. There's some leeway, but a 10% trim is excessive. Fuel injector cleaner might help. Nonetheless, not the cause of your issue.

I'd first check the grounds I mentioned previously, and if they're okay then replace the Bank 1 knock sensor. Here's a video; he shows the location of Bank 1's sensor at ~2:00. It's under the intake plenum. Your wiring could also be damaged as it is in the video.

 

So yesterday I spent the most of the day taking apart the engine to get to the knock sensors. While doing so, I checked all of the wiring to see if there’s anything abnormal but everything seemed fine. Once I took the manifold out I noticed that the head gasket was leaking. So I ended up taking off the valve cover and tightening all the bolts holding the head. Hopefully that fixed it lol. The manifold gasket was pretty bad as well and there was a lot of build up inside the manifold. Is it carbon build up? Wasn’t sure if that’s normal or not so I ended up taking out the manifold and cleaning it thoroughly.
While there, I took out the injectors and cleaned them as well. It seemed like some of the leaking oil passed through the injector o rings? Or something else happened? Either way, I cleaned up the manifold, injectors, replaced BOTH knock sensors, replaced intake and exhaust manifold gaskets and put it all back together.
Once I was done, I test drove the car for well over an hour and another hour this morning. So far, it seems like the problem is gone. And hopefully it stays that way! Bad knock sensor was likely the cause. I’m not sure cleaning the carbon build up and putting new gaskets would do anything lol. I’ll keep everyone updated.

 

You may have a stuck-open PCV valve allowing excess oil from the crankcase to enter the intake. I think excessive piston blow-by can also cause this. The carbon in Bank 1's intake plenum does look like a lot. As for the carbon on the injectors, that's normal and just from combustion. I hope you used nothing more aggressive than electronic cleaner.

How did you see the head gasket was leaking?

 

Interesting. I actually cleaned the PCV valve a day before tackling this job. It had some sludge but seemed to move freely. As for the injectors, I used a soft wire brush to get the sludge off and then wipe it off with an injector cleaner before I poured it in the fuel tank the next day lol

I first saw the head gasket leak when looking at the engine from the front. The right side corner was leaking. And then when I took off the manifold I noticed the head leaking where the gasket material is visible.

 

I've had a dirty PCV cause shifting concerns such as TCC apply shuddering, and I replaced it at one point with a WVE part from RockAuto. I read a post somewhere saying PCV valves are actually poor-tolerance parts and some are bad from the factory. I'm quite certain I can tell a difference after cleaning it, which I now do every couple thousand miles. It can still move freely but I clean it so that it rings when you shake it.

 

It’s been couple of days now and the problem hasn’t come back yet. I did end up replacing the PCV valve just in case. It’s less than $10 for the part so might as well replace it.