so Monday was the day i changed the spark plugs, spark plug wires, changed the oil and cut the muffler..

i cut it because the end of it was rusted open towards the back so i cut it before the cat so it couldn't rattle anymore but now it is extremely sluggish first and second gear to get up and go..i was told it has too much back pressure and the pipe needs to be longer.. ive never heard of there being back pressure on a naturally aspirated car..i don't see how that would work because there's cars running on straight headers and there's nothing wrong with them..

 

ive been askin the same thing.. were straight headers right now, exhaust came off on the 10fwy big mess haha. just got this ek9 ***** still in progress.

 

the car also idles very low..
i was told it could possibly be my idle controller.
or a vacuum leak maybe?

 

you should be idle around 600. if the iacv(idle air control valve) it would idle low then high and fluctuate frequently

 

loss a backpressure can cause a car to run weird same ex. factory exhaust is restrictive and a hp exhaust increases hp by reducing bp but not by too much. just my .02