Hey guys ever since I put the Y-pipe and 300zx fuel filter on I've been getting horrible gas mileage just driving around town as usual and even worse on the interstate.

My question is this, could a leaking flex section cause worse gas mileage? (bees in the can).

Or, do you think I need a tune some way or another because of the fuel filter?..

 

thats wierd you got CEL??? or may be its not working and you need to go to autozone to get it checked that if you got any codes or not

 

Yeah I should go check, this is true. But the only SES I was getting is for the EGR and I dont give a flying fawk' about that so.. I think it may just be mechanical as my question implies.

 

check for fuel line leaks, do u smell gas ?

 

I just checked teh nuts from my y-pipe to teh exhaust maniflods, & all 6 were lose!!!

My gas mileage has been better after I tightened them.
Might wanna check those to make sure they're snug.

 

you could have a exhaust leak from the y pipe and also the 300zx fuel filter is bigger than the a32 fuel filter that could be another problem check around and youll most likely find the problem

 

300zx filter has nothing to do with him losing gas mileage

 

Ok guys, OP is messin with you....

 

Well, he's messin with you (not me) then....

But seriously, check teh nuts that go from teh y to exhaust manifolds to make sure they're snug.

 

how would a leaking exhaust cause worse gas mileage?

 

Because the y-pipe holds the O2 sensors and if they are lose to the exhaust manifold then the sensors read lean because air is escaping.

 

agh i didnt even think about that.

i feel like i've got a leak but i just can't tell. i know one of my 02 sensors wires got cut so i need to solder them back together and see if i get a drastic gas mileage change. but this has me thinking about how accurate a wideband 02 sensor will be if i've got leaks further up in the exhaust.

 

The 300zx fuel filter thing was a joke..


But, in reality I've lost mpg in the last few months.. I believe its the y-pipe so I'm gonna check that. I just more or less wanted assurance that I had the right idea checking the manifolds.

Okay, okay dammit I know I had the right idea. I'm just the laziest basterd on this .org and don't feel like jacking my car up and fixing the problem.

 

so would u like one of us to come over and fix it for u ?

 

and bring some bacon with you.

 

mmmm canadian bacon

 

yesssss..

 

Maybe one of the O2 sensors is bad?? I recently replaced a bad O2 sensor. While bad it went down to 19-20 MPG. Now its back up to 25-26 (both under city/hwy mixed driving).