Slip light blinks

my car 92 q45 is having some problems and i cant figure it out.its doesnt wanted to go over 2000rpms - 3000rpms.it gradually got like that.it runs a little rough.this is what i done to the car so far:one of the coils,spark plugs,maf sensor,fuel filter,had the fuel pressure checked,the cats,and it got alittle better.it would go upto 5000rpms driving and that was at the end of december.now it runs like i wrote.the tranny shifts fine and it doesnt run rough after about 1500rpms.i heard alot of different things it could be.i took it to a friend and he said that he thinks it is the tranny cause when its in park it runs bad but in neutral it runs better.he also said the slip light blinks when he drove it(but i just think thats because the day he drove it it was raining and the tires were slipping)but he thinks that means theres something wrong with the tranny.can anyone help me out?did anyone have any similiar problems and what was the outcome? does the slip light have anything to do with the way the car runs and performs?and would the tranny affect the rpms on the motor?

While I’m not intimately acquainted with your Q45, your friend’s experience would point to a traction control system that’s (perhaps) reading faulty data from some ABS sensor. That can play havoc with the engine speed. There should be a way to disable it with some clicks of the shifter button thingie.