i finaly got my hf to pass e-check after i replaced the cat, but it is still getting only like 32-35 mpg. i have replaced the cat, egr, pcv, plugs, cap, rotor, wires, and completley cleaned out the egr passages. the idle was under control but i s now back to around 1200-1500 rpm. there are no codes so i dont know what to check next. all emission readings seem to be average.
1991 Hf 130,000 miles
stock engine,exhaust
only mods are wheels (14's from a VW) and lowering with some cheap coilovers.

 

ok the 14's are hurting your gas milage because bigger wheels take more power to roll ,hows your air filter looking ,and are you using the idiot light thats all i can thank off

 

^^^ as said above damn that is some shitty gas milage for an hf

 

fuel filter
Lucas fuel injection cleaner
Oil change/w oil filter
Air filter
Check the psi of the tires
As for your idle..Check the iacv..That affects the idle..If it's dirty and clogged ,change the screen and clean it out with some carb cleaner..

 

bump any other ideas

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mrspeaker &raquo;</TD></TR><TR><TD CLASS="quote">fuel filter
Lucas fuel injection cleaner
Oil change/w oil filter
Air filter
Check the psi of the tires
As for your idle..Check the iacv..That affects the idle..If it's dirty and clogged ,change the screen and clean it out with some carb cleaner..
</TD></TR></TABLE>
^---------------- beat me to it.
The fuel filter, the 02 sensor on the manifold, and if you are really desperate do what i did and rip the IM off and run about 10 cans of carb cleaner through it and get a small toothbrush and peel all the Carbon off the inside...