Just got a 98 GTP yesterday and have this code. I believe vacuum is tight because I tested with TB cleaner. Car doesn't have a diagram so I may have missed something. MAF looked fine but I cleaned it anyway, put in new PCV and Air filter. Previous owner says it was a recurring problem and he's a car guy you should have seen the ponchos in his garage. I have a scanner what data is in the norm? I also dropped a bottle of techron in the tank but that will take some time to have an effect. car runs really well despite code.
