Hello Folks,

Getting about 10 MPG all city.

Plenium is fixed, thing bogs all day (red light, 3/4 gas takes like 10 seconds to get to 35). All new/plugs/wires/cap/rotor,etc.

Know I was told before o2 sensor looks sluggish, would a new o2 sensor possibly help my MPG and performance a bit?

And NGK's the way to go?

 

Did it bog and take forever to accelerate before you did the plenum fix and new plugs,wires,cap,and rotor?

 

Not sure, bought the truck with all those installed 2 weeks prior, and it dosn't run. Replaced the plugs two times to them fouling out (motor was running real rich).

Might try another set of plugs again (replaced them when motor was running rich, haven't checked them since). Also the muffler has a broken baffle too according to my dad, could that cause the bog too?

 

Before you mess with the muffler or anything else. Make sure the wires are hooked up in the correct firing order. If they are, pull out your o2 sensor on the catalytic converter, you will get a check engine light, but see if the motor runs better, if it does, you need a new cat. Hope this helps some. After you get it running a little better, do the sea foam treatment.

 

buy these. I had them on my 5.2 with the 92 octane chip and i got 16 MPG city.
http://www.fiveomotorsport.com/domes...rs/?itemid=297

plus a lot better throttle response. Much better than my current STOCK 5.9

 

You probley have whats called the "death flash". Its what dodge used to cover up the plenum issue. Search "death flash" it will tell you all you need to know.

 

+10 on deathflash




also when you did the Plenum, you used a Hughes or APS kit right? if not the plenum probably blew out again...you cant just replace the gasket....

 

3/4 gas and can't get to 35 mph. something's really ****ed up beyond a little death flash.

could be front 02 sensor, could be clogged cat.
got any cel codes ?

 

If it was running incredibly rich.... what about a coolant temp sensor? On the GM's I worked on, the coolant temp sensor would fail, convincing the computer it was like -40 degrees.... so the computer would quite literally flood the engine.

 

I'd take out 02 sensor like mentioned above first. I would think the broken baffle could be plugging the exhaust at the muffler, possibly. If it doesn't help, you will rule out exhaust/cat and can go from there.