hello, i am hoping that someone can help me out with an engine light that recently came up on my 1999 rsfour (rb25det).
it is code 21 which is "ignition signal" (I checked the code using the paperclip method) I read that it could be coilpacks or spark plugs. I have since replaced both (r8 coilpack upgrade) and the same ngk spark plugs that were in the car already. I should also mention that the check engine light does not come on until the car is at operating temperature or about 5-10 minutes of driving. the car also does not seem to have any difference in performance at any rpm.
if anyone has any suggestions on what else to check for it would be appreciated.
thanks!
