Cold mornings engine "chugs" and check engine light flashes

[LoxRunner]

Had 2 occasions on cold mornings recently (about 40 degrees) when I started my 2002 4runner (170k miles) and after turning over just fine, the engine seemed to "chug". Idle was at normal range for a startup, around 1100, but engine was sounding sluggish and chugging. This lasted for about 1-2mins, then my check engine light came on and started flashing. Even after warming up and the engine became normal, the CEL was still flashing. Turned the car off and back on, started fine no problems and CEL was off and stayed off.

Even on other similar cold mornings the car started fine, this has only happened twice. I'm only concerned really because of the CEL flashing. Any ideas?

 

[Konkordmusk]

A flashing check engine light means you have a misfire. Scan the engine computer for codes and proceed as the codes dictate.

 

[StreetCreeper]

Had 2 occasions on cold mornings recently (about 40 degrees) when I started my 2002 4runner (170k miles) and after turning over just fine, the engine seemed to "chug". Idle was at normal range for a startup, around 1100, but engine was sounding sluggish and chugging. This lasted for about 1-2mins, then my check engine light came on and started flashing. Even after warming up and the engine became normal, the CEL was still flashing. Turned the car off and back on, started fine no problems and CEL was off and stayed off.

Even on other similar cold mornings the car started fine, this has only happened twice. I'm only concerned really because of the CEL flashing. Any ideas?

Yep, like Konkordmusk said, check the codes first then proceed from there.

 

[BamaDrewski]

Had 2 occasions on cold mornings recently (about 40 degrees) when I started my 2002 4runner (170k miles) and after turning over just fine, the engine seemed to "chug". Idle was at normal range for a startup, around 1100, but engine was sounding sluggish and chugging. This lasted for about 1-2mins, then my check engine light came on and started flashing. Even after warming up and the engine became normal, the CEL was still flashing. Turned the car off and back on, started fine no problems and CEL was off and stayed off.

Even on other similar cold mornings the car started fine, this has only happened twice. I'm only concerned really because of the CEL flashing. Any ideas?

Not sure if this will help you man but I have had something similar to this in the past and it was a faulty TPS (Throttle Position Sensor). As previously mentioned, it could also be your plugs. The TPS does go out and it will throw a CEL. If and when you replace it, use a Toyota OE TPS. I bought an aftermarket one time and was lucky if it worked for 4 months before crapping out. Good luck and be sure to post the solution that worked for you.