i have a 93 truck a K&N air filter, 2.25 exhaust w/ a flowmaster muffler and i think its a pacesetter header. and since i have installed the header and exhaust i have seen no improvements in at all if not decreased power. would it be possible that its not getting enough fuel ? and would a fuel pressure regulator help me out? any help will be greatly appreciated
thanks
jon

 

I closed loop the injectors are going to adjust for the extra fuel you'd be providing with more fuel pressure.

Changes like these don't necessarily result in seat of the pants improvements. If you think you've really had a power decrease and suspect mixture, you could install a basic air fuel gauge and see what the results are. Properly functioning, the AF gauge should "dither" or move back and forth from rich to lean at cruise. WOT should probably be in the rich range.

 

You already have a fuel pressure regulator...or should, anyway, if it's EFI. I'm assuming it is.

As he said, a fuel pressure gauge would help, but only in monitoring the pressure. I won't help with performance, though...obviously.

How long have you been running this set-up? Has the check engine light come on at all?