Date registered: Apr 2008
Location: New York/Moscow
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
I think the seller would be a d*ck for NOT allowing you to use a code reader.
Last summer I almost pulled the trigger on a 1999 SL500 at Carlisle car show (I was in a depressed mood and thought it would cheer me up). Check engine light went on during my otherwise joyful test drive, seller said it must be the gas cap. I said that I would get my reader and be back in a few minutes, he said he can't allow me to use one as it might damage the car's electronics. I imagine a PPI would have been out of the question. He did save me a lot of money!
If the seller has something to hide, he can always say no to PPIs, to OBD readers, etc. Even to test drives. There will always be someone who comes along more naive and buys without investigating first.