Hey all,

Was hoping for some advice. My Astra G has started acting up in the past few days. It seems to be misfiring or jerking, particularly under acceleration. This is also leading to power issues, surging etc.

The CEL is off, but it has flashed up a couple of times. No other ligths are on. The codes that have come up are as follows:

P1500 , P1550, P1630

From my Google-Fu, I think that this suggests that there may be a problem with the throttle body (hopefully just needing a clean), but would it be wise to change the spark plugs as well?

The temperature gauge (or a sensor, most likely) also doesn't seem to be working consistently. The needle doesn't seem to move for a long time. When it does, it sits in the middle for a bit, then drops back off completely.

Bit of background:

I've only had the car for a couple of months. I bought it privately and was told going in that there was an issue with O2 sensor. £300 later and the O2 sensor wasn't the issue, someone had been monkeying with the ECU and had bent a pin. The ECU has been remapped, the O2 sensor replaced etc. That was 6 weeks ago and the car has been fine ever since.