Well, I have a Warpspeed exhaust from the heads back, but the muffler rusted out and a hanger weld completley broke off. So I replaced it with a new stainless steel magnaflow muffler. Only problem was that it was .5 inches smaller than my warpspeed pipe but the guy at the muffler shop said it wouldn't be a problem to make them fit. Well it fits, it is fully enclosed, but the pipe bends are pretty crude and I have been noticing a 3 mpg drop in fuel economy... Should I just get it replaced with a mandrel bent piece? Is the drop in pipe diameter what is causing the drop in economy? I have recentley replaced my fuel filter as well.

Eric

 

Pic's would help us get a better understanding of the situation

 

you sure you aren't driving a bit more agressively with the upgrade? it should actually help mpg a little but it is not uncommon to take advantage of the extra power...

 

well, when i had my muffler changed on my 3rd gen to a magnaflow, i found myself driving a bit faster to cut down on that damn exhaust drone. so...you maybe doing the same without knowing. faster cruising speed, milage drops.

 

I will post some pictures tonight.

 

reset computer after every upgrade.

#1. Pop hood
#2. 10mm wrench to unplug both power and ground.
#3. Wait one hour
#4. replace battery cables
#5. go for a drive (20 mins)
#6. FELL the POWAH!

 

The WSP piping is 2.5". If you have reduced that with a 2" pipe and muffler, then I would take it right back to where you got it done, and have them replace it with an equal pipe diameter.

You did say.5" smaller pipe right?

That's a 20% smaller pipe diameter.

 

IMO the ECU in the older Maximas are as stupid as can come and do not retain intelligent "statistics" or environment variables after switch-off with which to "tune" the control system on a continuous basis, so a complete ECU reset is unlikely to have any effect at all unless you have a really screwed-up electrical system that somehow managed to corrupt the normal workings of ECU ....................

Can you say what info you base your comment on?

 

My Hinney Meter....

 

In serious need of re-calibration I would think ..................

 

Possibly.