not as much power on the highway

[tdowns21]

Hello I'm new here and I just recently ran.into this problem with my 98 Tahoe 4+4 I do have a check engine light on for cylinder 6 misfire (spark plugs or wires) but it's been on for a week now and never had this problem before until yesterday. When I'm on the highway I normally run about 70mph and now it seems to struggle to get there and when I push the peddle to the metal it barley moves just sounds like it the transmission shifts fine threw all gears idk what the problem is. Limp mode maybe?

 

[samotahoe]

could be a problem with cylinder 6? bad spark plug or wire?

 

[tdowns21]

thanks ill change everything tomorrow and ill find out