Help with car issue (check engine light)

JMB2024

Dear all,

First post for a while. The last time I got some really useful help regarding a problem with my old Astra. I ended up getting someone to replace the EGR valve which fixed it.

This time, I had a problem with the car almost stalling on idle and being slow to accelerate. The diagnosis at the garage was throttle body. This was cleaned and now the engine idles properly. However, the check engine light is still on and the car is slow to accelerate (I think it's in limp mode but I'm no expert). I have an OBD code reader but it says there are no fault codes. I've also tried the throttle body relearn procedure whereby the battery is disconnected for 10 mins then the car is left to idle for 10-15 mins. The check engine light just comes straight back on and revs are still limited.

My uneducated guess is that I will probably have to have the throttle body replaced, but I thought i'd check in here to see whether there is anything obvious that i've missed or could try first?

The car is a 2009 astra estate diesel 1.7l and it's done 95K. 

Thanks.