My car is a 99 exv6 with 219k miles on it. No check engine lights on.

When I accelerate, the car runs to about 2000 rpm then it drops to about 1500 rpm then when it reaches 2000 rpm again it starts to lose power after about 2000rpm then the rpm needle pulsates between I would say 1500 rpm and 1600 rpm. When that happens the car is at 25mph. If I take my foot off the gas then press the gas pedal again, it then goes pass 25mph and it drives and feel normal.

This happens normally when car has been off for a long time like in the mornings or at night when I leave work.

This all started happening like 2 days ago. Last week I noticed that my right muffler was hanging down and when I looked underneath, the two rubber holders were not attached to the car, so I reattached them. Then when I turned on the car I did noticed that in the front end of exhaust system, smoke comes out of the braided part of the exhaust pipe like if it's the muffler. Now smoke still comes out of the muffler but also from this braided section of the exhaust. Can there be any relation to that and the cars current performance. Any ideas and suggestions are welcomed and helpful.

 

Suggest inspecting/repairing the EGR system as indicated.

EGR manifold blockages can cause uneven distribution of EG leading to overlean cylinders and missing/sagging performance.

If you disable the EGR valve by removing vacuum actuation (likely to set a code) and this relieves the problem (no EG injected), then EGR manifold needs to be accessed (not easy on V6) and cleaned. Youtube videos may be helpful.

good luck