Flashing CEL and Misfires

[GennyGuy]

So in the last 2 weeks, I've now had a flashing CEL twice. I do not have a log as I wasn't racing or doing anything out of the ordinary. Both times the flashing CEL has occurred right after start up and acceleration. Wasn't going fast, both times under 40mph. Spirited acceleration though (3800 RPM). Cylinders 2,4, and 6 are showing a misfire code simultaneously. However, there are no other error codes identifying what could else be going on. For those that don't know, those cylinders are all on the same side, the driver's side. CEL flashed for about 10 secs and then went away as if nothing had happened. I have tried over the last few days to replicate the conditions and "force" a CEL , but nothing. The car is driving perfectly normal and is still willing to go all out with no issues. But a flashing CEL should never be ignored.

I have a 2021 G70 Sport 3.3T AWD.

I'm kinda at a loss for what could be triggering it and wondering if anyone else has had something similar happen where there's multiple cylinder misfires. Thoughts?

 

[MerlintheMad]

You start up and accelerate at once to 3.8K RPM? I have never done that: always get the engine up to temperature before pushing much beyond 2K RPM.

Also, I've never seen a flashing CEL, only a steady CEL, and that was when I had a bad sparkplug and boot/coil (cylinder six).

 

[G70LEbyAdoom]

Sounds like its time to open her up and check the plugs to see if they are damaged, for sanity sake. if nothing looks out of place, put your OEM tune back in and see if it happens still.

 

[GennyGuy]

You start up and accelerate at once to 3.8K RPM? I have never done that: always get the engine up to temperature before pushing much beyond 2K RPM.

Also, I've never seen a flashing CEL, only a steady CEL, and that was when I had a bad sparkplug and boot/coil (cylinder six).

It wasn't a cold start and no I generally do not do that. The first time, the car was off for 10 minutes. The second time, a little less than an hour. Both times the vehicle had been driven for at least 30 minutes prior to shut off.

 

[GennyGuy]

Sounds like its time to open her up and check the plugs to see if they are damaged, for sanity sake. if nothing looks out of place, put your OEM tune back in and see if it happens still.

I doubt it's plugs because the misfire isn't constant. I also just changed a coil pack on cylinder 3 a few months ago. This is intermittent and the misfire even feels different if that makes sense. It would be a little too odd for only the plugs on one side to be bad. HKS plugs are installed for anyone wondering.

 

[G70LEbyAdoom]

I doubt it's plugs because the misfire isn't constant. I also just changed a coil pack on cylinder 3 a few months ago. This is intermittent and the misfire even feels different if that makes sense. It would be a little too odd for only the plugs on one side to be bad. HKS plugs are installed for anyone wondering.

well thankfully its happening on the easy side (If memory serves) so it shouldn't be that hard to check for sanity sake.

 

[GennyGuy]

well thankfully its happening on the easy side (If memory serves) so it shouldn't be that hard to check for sanity sake.

Yeah, I'll do the sanity check. But gut tells me something else.

 

[General_Vodka]

Loose connector somewhere maybe?

 

[GT Elite]

Brainstorming. I wonder if it is a faulty O2 sensor that is telling the PCM that bank is running rich, which it isn’t. So the PCM leans out the fuel to the point that that bank is running too lean to the point it is mis-firing.

 

[GennyGuy]

Brainstorming. I wonder if it is a faulty O2 sensor that is telling the PCM that bank is running rich, which it isn’t. So the PCM leans out the fuel to the point that that bank is running too lean to the point it is mis-firing.

My buddy threw that idea around. Gonna get a price on it today.

 

[GennyGuy]

Loose connector somewhere maybe?

It's possible, but I couldn't see anything. I did notice a hose that seemed pushed back quite a bit, but the connection was still super tight. Boost spike? Idk. I'll add a photo when I get to the car.