Someone told me on here(Icant remember who) that the y pipe is very restrictive. I wonder if you can buy a y pipe and just replace it with no other pipe.

 

Ok sorry guys I did a search and found a couple things but wasnt going to dig into 10,000 pages of crap lol No sense in starting a thread when this one isnt that old. Sorry for the hijack.

Anyway have a 07 quad cab hemi big horn edition 20in wheels all stock except for bed cover but I know that will barely make a difference anyway. Mind you it also has mds(weather that helps or not idk) Last year was getting around 13-14 in town and 17 highway best was 19. Winter came and mpg dropped so I expected that(couldnt get over 13 mpg highway city was about 8-10) Now its warm here and still no increase in mpg. Still getting 13 highway and about 10 city. With gas being almost 4.00 a gal it would really be nice to get my old mpg back again. Tires have proper air in them air filter doesnt even have 10k on it still looks good. I have no clue whats going on? Truck only has 37k on it. My other question is when do you guys recommend the spark plugs should be changed?

 

As per the book, 30,000 miles...

 

Alright then looks like im going to pick up 16 plugs then. That will be a fun job!

 

I am getting 16-17 here in WV with the mods you see below in my sig

 

Im going to do plugs(need done anyway) and ill put in a new air filter just to see, heck only couple bucks anyway. Then we will see if the mpg increases. Prob wont get done till next week tho since Im working on the dakota this week.

 

I just think i fixed my problem. I have been running 91 octane which is only around $5 more for a whole tank than 87 octane and im getting 15mpg highway at 70mph which is reasonable. I was getting 10. Im hoping the higher octane will help clean up my motor also. Does 91 clean up your motor? sludge and carbon wise? That would be sweet.

 

If your changeing all 16 plugs make sure you got lots of tools. 8 on top of the engine and 8 on the bottom. You have to have various extensions as well as a swivel attachment for your socket.

Where do you buy your gas? For me sunoco 87 octane does alittle better than most other places.

 

Oh I got lots so thats no a problem. Why would you only change 8 of them doesnt make sense to me. I figure while your in there might as well get it over with.

 

I don't know what engine you have but my hemi had all 16 plugs on the valve covers side by side.