I recently acquired a 1989 300SE with 160k miles (beautiful car, in general in very good to excellent shape). due to various reasons (not inherent problems with the vehicle), the head gaskets had to be replaced, as well as the timing chain and two valves. I have two questions. First, I wanted to know if the following is a concern. In drive at idle, the economy meter goes to halfway. when I accelerate to around 25 mph and take my foot off the pedal, the economy meter goes to the far left. Is this normal? In Park, the needle holds steady around the first c.

Secondly, this vehicle barely passed emissions. I inquired the buyer about it and they said this was normal for a car of this age. I am inclined to be skeptical of this based on what a friend told me.

CO %
limit .79
reading .33

HC ppm
limit 140
reading 103

NO ppm
limit 1046
reading 1034

I am just concerned that next year, I will get a failure on the NO or the HC.

Thanks for any help you can give.
Ben K