Picked up my 96 Passat GLX VR6 at the shop the other day from getting a new radiator and the check engine light is now on and the transmission shifts poorly - delayed upshift and occasional clunking. Wondering if they could have nocked anything around on the radiator job that would cause that. Any ideas?

Also wondering if the right thing to do next is have it scanned to see what the check engine message is. Seems logical, but around here that costs 100 bucks.