Well unfortunately problem still exists this am at 25 degrees out. Not as bad but still a tiny rough idle issue for a second. Other conversations people say it’s the O2 at the flex pipe after they changed the evap solenoid. But O2 sensors make the engine run crappy all the time.

Only engine I have ever had that had check engine lights. So this is all new to me and I’m learning. But shops/dealerships just throw parts at lights as well and charge $100-plus just to scan it. So trying my best not to go that route! Still stumped solenoid made a big difference…

Can someone post values of what all sensors should read when in park and engine running. Like Maf, IAC, O2 sensors, etc. then when I’m looking at my scanner I can see if something is off.

 

Also in 2018 stock MAF sensor went bad. Only symptoms I had was on a trip it starting getting sluggish acceleration and light came on. Shop said that was the issue and used a refurbished one. Mechanic said these engines are great but MAF will fail if E85 isn’t used. I was like hmm never heard that one and I doubt using 87 for years then switching to 89. Then crazy gas prices I went back to 87 months ago being the issue. Owners manual says use whatever.

 

The O2 sensors don't work at all until they heat up.
E85 is not an octane reading like 87 octane gas; it is a percentage of Ethanol. That guy is crazy. 89 octane is recommended for a 2.4L engine.
What does "went bad" mean? They don't malfunction often, usually the connector gets loose or forgotten after an air filter change.
Did you ever look at the air horn checking for cracks and loose connections?
Check the intake manifold for cracks and loose connections?
Check all hoses for cracks and loose connections?
Check the vapor return line for holes and loose connections?
Clean the throttle body?
Check the throttle body to manifold connection?
Exhaust manifold gasket and torque and cracks?
Fuel pressure?
Check the O2 sensors for color of deposits? White powdery is bad.
#1 O2 sensor should give very rapid variable voltage readings, #2 O2 sensor should be steady somewhere between .1V and .9V

 

Wonder how long it takes for O2 sensors to heat up?
Thanks for sensor info’s.
Yes myself and buddies checked all hoses, connections. All wires are good, throttle body is clean. Checked all over exhaust multiple times no cracks, no exhaust marks anywhere on pipes or around 02 sensors. Will check fuel pressure again but odd to be that too as scanner showed good but will use a manual gauge instead. Can’t scroll up and see what else you asked but I don’t know just dropped HHR off and they said MAF wasn’t reading correctly. Other then that no other info. I don’t think it hurts running 87 in a 2.4L does it?

Also wonder why it doesn’t throw a code for any of the other parts that might be bad? Odd like I said how purge solenoid helped..

If it was vent valve by gas tank it should through a code for that?

 

Don can you please PM me your email address so I can send you a video of my scanner it shows everything some of things I’m not sure what they are so you can please look them over and tell me if you see anything that’s wrong. Also it showing a P0014 exhaust cam position sensor.

 

P0014, possibly wires loose, a stuck valve, very dirty oil, ground wire.

https://www.obd-codes.com/p0014

Your MAF , what brand?
Your VVT solenoids, what brand?

How long since they were changed?

You posted your timing chain was changed not long ago, what brand?

 

No idea on brand of MAF I would assume from a local parts store the shop used. Napa, autozone the likes.
Changed VVT solenoids with autozone parts and think Acdelco at 100,000 miles. I have 163,000 miles now on engine. Oil is still good for awhile and has marvel added to it like we talked about. Haven’t checked any grounds. Wiring harnesses are all good. Odd for it to all a sudden pop the new code. Could the bad thermostat have caused this codes from running lean and computer making it rich trying to fix issue? 140,000 miles timing chain was replaced no idea on brand. Probably Napa.

 

My theory is the electrical connectors, loose pins, bent pins, corrosion.
You MAF might just need a good cleaning, use Sensor safe MAF cleaning spray!
I am also thinking the aftermarket parts might not be as dependable as AC Delco or Cloyes. Just saying, I’ve replaced a timing chain stretched at 25,000 miles! Changed VVT solenoids at less then 10,000 miles, those were aftermarket parts the PO installed, still they failed!

 

I called shop and they said Napa is only business they deal with. So timing chain is good quality.

Maf was already sprayed with electrical cleaner.

Im going to pull VVT sensors and clean them off and see what happens.

We don’t have any salt on roads here and to be honest nothing is rusted under hood. All harness are clean and don’t see anything wrong with them.

 

MAF needs to be cleaned with MAF cleaner, electrical cleaner can leave a residue, that might cause the MAF problem.