Hi There - I've been a lurker on these forums for a while...

I have a 2001 V70 T5. Last November I replaced the ETM with a Xemodex rebuild. I replaced the MAF sensor after that because I had some idle RPM hunting. The car has been running well since, but just over the past few weeks I've been getting rough idle, and now over the last week, stalls, sputters and strange lag on the highway. I pulled OBD code p1238 which I believe corresponds to the Boost Control Solenoid aka (Turbo Control Valve). I am checking for leaks in the vacuum system (and I realise I might have to replace the TCV, but I can't help but feel like the symptoms are also similar to when my last MAF sensor died.

So my question is: how can I check the MAF sensor without just buying another one? It looks clean and totally fine under inspection, after all its only six months old.

Do I just unplug the electrical connector while its idling and see if the car stalls?

Thanks for any insights.