new to k series and kpro need help!

[typesdano]

I just bought an 02 rsx type s from a friend of mine. He had installed skunk2 cams and valvetrain, DC header, greddy exhaust and kpro with papers and receipts to prove it. This car has not been tuned yet.

My question is sometimes the CEL comes on and I acquire a 2step and rev limiter at about 3800rpms in every gear. However when the CEL is off I do not have this issue and car runs normally. What could this be and how would I address the issue

[Spunkster]

Check the code and then correct the problem.