Hello all, lookin for a little advice (or help)

My 94 4Runner 5spd V6 just recently came out of the shop with new fuel lines and new fuel filter...

When I get going down the road it starts coughing or sputtering again as soon as I hit 2nd gear. The tech (trustworthy) told me my fuel sending unit was ok on when he replaced the rear line...

Does it need some HEET or SEAFOAM? How do I tell the difference if the prob is the engine opposed to the fuel system or exhaust?


Thank to all

 

How many miles are on the motor? Why did you need to replace the lines?

 

139k on the engine...lines were old and falling apart, any ideas??