What is the faulty part?

What is your question?

My 2000 CLK 430 presents two issues that might be connected, both having to do with dashboard check lights. The SRS hardly ever comes out in the check control before all lights turn off. On the other hand the Check Engine light often stays on (not always) for a while and when it does performance usually drops (but not always), especially in connection with my pushing down the throttle harder than normal. Can you help? Thanks very much, James.