Last week I installed a Koyo radiator. While I was flushing the radiator I got a CEL thrown. I installed the new Koyo, and the CEL light still remained on. Yesterday I reset my ECU by unplugging the battery for 10 minutes or so. When I turned the car on, the CEL dissapeared. I shut the car off and when I turned it back on about an hour later, the CEL reappeared.

Has anyone had this issue and know the fix for it? I know I should get the code pulled at AutoZone, but the only reason I am asking is because I work 8am-8pm Monday thru Friday and generally our AutoZones close at 8 or so. I will have to leave work early to get the code pulled, so I wanted to see if anyone had any ideas before I took an hour off of work.

Thanks!

Here is my mod list:

GReddy profec B spec II
Koyo Radiator
GReddy boost gauge
Apexi Power Intake
GReddy Type S BOV

what is the secret code?

I don't know, if you read my post I asked for ideas because it is very hard for me to get out to an AutoZone without skipping some work.

In any case, I just ran out and I think I solved the problem.

Hows the coolant temp while the motor is running?

Did you add any additives?

Make sure u have all electrical connections plugged in snug.

maybe u have a air pocket in the water jacket or something.

Ur best bet is to get the code read and go from there.