A couple months ago, I had a Warpspeed Y-pipe and hi-flow cat installed on my 95 Maxima. I have been tracking the gas mileage and see no real improvements. Any ideas?

 

your really not gonna see that much of a gain in mileage just from those they free up the exhaust you may gain but nothign extreme

 

Its not technically suppose to improve gas mileage.

It will give you more HP. You should have noticed it at 2 points. 1 Right after you installed the pipe. 2 When you drove about 200-250 miles after resetting your ECU.

I noticed a little increase at 1, and a huge increeease at 2.

Is your check engine light on? You may have a code for a O2 sensor or something

 

Why did you expect an MPG increase?

 

do the 60k mile tune-up. that should solve your mpg worries.

 

I heard that the ecu will readjust to the new mods without resetting, can anybody else confirm this?

 

Some people claim to gain mpg, and then some say that it makes it worse (probably due to their harder driving). I guess you should be happy that it didn't make your mpg worse.

 

i didnt notice any difference... all i noticed was the car got a lot faster after 3k rpms.. and dropped power down low...

 

Less exhaust restriction. I did notice a performance increase. Maybe I'll throw in a new set of NGK plugs.

 

To PSCMJ84: I see that you have a Warpspeed y-pipe installed on your Maxima. How do you like it? I saw a bunch of posts bad mouthing Warpspeed. I can't complain. My mechanic didn't mention anything when he installed it. Just that one of the manifold bolts snapped when he tried removing the old y-pipe.

 

I have to say that I can't recommend the Warpspeed Y-pipe due to the crappy flex section. It sounds like it's common for the flex section to leak, even brand new. When the flex section leaks, this causes a hissing sound under hard acceleration. I'm going to try some exhaust wrap on the flex section to see if that helps. You can read about it here:

http://forums.maxima.org/showthread.php?t=530821