I have Z20LET on ASTRA OPC 200HP.
Sometimes rough iddle.
I change mass air flow meter,same probleme.
I change Temperature water sensor,same probleme.
I change injector,spark plug,fuel filters same probleme.
The probleme comes not all times...
Sometimes 2 weeks all good..but sometimes rough iddle again.
I cleaned the throttle body assy.
Should i change this parts?
In workschop Opel in my country they use TECH2 tools and no trouble codes find.
Can you help me please.
Sorry for my bad English.