Air France Frequence Plus - Do I have time to leave Airport during layover?

I will be landing at CDG on an AF flight at 11:30am and I will be departing on an AF flight at 3:30pm. Do you think I would have time to go to a nearby restaurant to have a good piece of French Chocolate Pie? I know there is a good place downtown, but would I have time to get a taxi and run down there grab the pie, get back to the airport, go through security and get back to my gate? Would I have time to take in the Eiffel Tower? Does anyone know of a good restaurant for chocolate silk pie near the airport that I could go to? Yes I love going to France I just don't know about this connection time. Merci

It does seem a bit short. Perhaps you could specify the terminals or the destinations involved, in order for us to give a finer grained assessment of the feasability, but I personally would not try to reach dowtown Paris with just 4 hours between my flights ! You might try to call the Sheraton at CDG or Brasserie Flo in Terminal 2F to check whether they serve you variety of chocolate cake, but I would not go much farther from the departure gates.

This is what I have but I would love to know the terminal any help would be appreciated.

Manchester, United Kingdom to Paris-De Gaulle, France
Delta 8449 - Operated by Delta Codeshare Partner, Air France as Air France 1669
Carrier
Flight # Departs Arrives Equipment
Type Flight
Duration Miles
From Time To Time
Delta 8449 Manchester (MAN) 9:10am Paris-De Gaulle (CDG) 11:35am 319 1.25 366
Total miles: 366

Paris-De Gaulle, France to Atlanta, GA
Delta 8504 - Operated by Delta Codeshare Partner, Air France as Air France 304
Carrier
Flight # Departs Arrives Equipment
Type Flight
Duration Miles
From Time To Time
Delta 8504 Paris-De Gaulle (CDG) 3:55pm Atlanta (ATL) 7:20pm 772 9.25 4394
Total miles: 4394

Also do you have any idea how to get a seat assignment on a codeshare? And what seats should I request on these flights?

Your flight from MAN arrives at Terminal 2F2 (non-Schengen) and your flight to ATL leaves from Terminal 2E (also non-Schengen).

Flights from 2E leave either from the boarding area built alongside the main 2E buildings or from a remote satellite which is reached by bus from the main 2E building. Leaving from the remote satellite involves adding 45mn to your transfer time. So this reinforces my belief that you have absolutely no chance of going to Paris and getting back in time for your flight.

You have two options :
walking, landside from 2F2 to 2E; this involves entering France in 2F2 (usually quick, especially around 11.35 AM) and going through immigration a second time upon departure in 2E. This gives you the opportunity to go to Brasserie Flo (in 2F) or the Sheraton hotel (above the TGV station).
taking the airside transfer bus, which does not involve any immigration check, as you are not entering France. The shuttle may be slow, at peak times, but this is not an issue in your case

I would definitely choose the first option if your flight from MAN is on schedule, as there is not much to do in 2E airside. In both cases, you will need to go through security checks, as is the rule in French airports, even though you are transferring through CDG from another airport.

Enjoy your flights :)

What are the best seats on these type of aircraft?