98 corolla problems help please

bikersteve2015

Hi i have a 98 bug eyed corolla lately my fuel consumption has gone through the roof im barely gettin 200 miles to a full tank also i noticed my top end speed is ****e im only gettin 100 miles an hour where i used get 120 only 2 weeks ago also i noticed she sputters when j put the foot down in second and third gear any ideas on what could be causing this as im stumped. Jnput in new plugs and ht leads to no avail. I also changed clutch as she was ****ed dont know what else it could be. Please any help id appreciate it.

Aint Eazy Being Cheezy

I'd say if you stopped driving at 100mph your fuel consumption would improve.

bikersteve2015

I dont do it all the time im just making a point that its down on power

Aint Eazy Being Cheezy

Air flow meter, coil pack. Could even be the start of the head gasket about to go.

bikersteve2015

Ill change the coil pack see if it makes a difference
how would i diagnose the headgasket ill try sort it before it blows

Aint Eazy Being Cheezy

Check for white gunk around the oil cap, check coolant levels. Once it doesn't overheat you may get away lightly.

Stop driving the stones out of her too, because you'll kill it.

bikersteve2015

As i already said i dont drive the stones out if it also there is no gunk there and coolent levels are ok and not overheating