pulstar spark plugs

[Norm reynolds]

Ok I am trying to play around with my 04 Jeep Grand Cherokee
It has a 4.0 in line six cylinder motor when I bought this jeep I had a 91 full size blazer
350 with 35.in tires had 195000 miles on it and was sick and tried of the 8 mpg I was getting so I down sized to a old reliable in line six jeep but was just as bad getting around 10 mpg in the city
went back to the dealership a 100 time”s and was told all was well and that all I can get out of it
well today they are now saying we might be at 5 bucks a gallon before the end of summer
so I started out with airing up the tries drop in a new air filter then Monday I changed the oil and the rears fluids I went with Royal Purple because I had a lot of problems with Mobil 1
Now I used RP 5x20 for the motor oil as was recomended on Dr Hass oil report
The factory used on the rears as like 75x140 Mainly for rock climbing and towing witch I do not do
I used 75x90 RP in the rears I then went on a 40.mile trip on the highway
set the cruse at 60. Normal I was getting 18 mpg tonight she got 24.6 and that is with the a/c on with 4.0 .So I think that is a good start
so I am on a good start there is a lot more I want to try
leaning out this beast IS NOW the # 1 thing
I did look at the plugs and they are Black My tail ,pipe is very black and as I was under it every exhast jont has all this black powder even my muffler is black so to me this is running very rich
went back to the dealership and showed them and they said yep it running rich BUT they can not legally change the factory pc settings In my family we have four jeeps and They are all running rich
I found something about building a the map sensor adjuster were I could change the single wire to the pcm for 5 volts to 4 volts but radio shack does not have the parts also have been reading about wide and low range o2 sensors but I still not understand how they work over stock sensors last night I was read up on this spark plug called Pulstar that is suppose to help l lean it out but I don’t know if just some scam because they cost 45.00 a plug”””” At that price I do not want to experiment and end up with nothing has any one heard of this and are they as good as they say
and lastly does any one know how to hack the pcm I was told that the factory has the fuelflow rate set at 19 at idle I was all told if I did hack it and set it to 10 then the mpg would jump right up
http://www.pulstarplug.com/index.html